experiments in ap psychology

AP Psychology: Understanding Research Methods

In AP Psychology, a deep understanding of research methods is essential for interpreting psychological studies and conducting empirical research. Here's a comprehensive guide to the key research methods studied in AP Psychology:

1. Experimental Research:

   - Objective: Establish cause-and-effect relationships between variables.

   - Design: Random assignment of participants to conditions, manipulation of an independent variable, and measurement of dependent variables.

2. Correlational Research:

   - Objective: Examine relationships between variables without manipulating them.

   - Design: Measure variables to determine the degree and direction of correlation. No manipulation of variables occurs.

3. Descriptive Research:

   - Objective: Observe and describe behavior without manipulating variables.

   - Design: Includes naturalistic observation, case studies, and surveys to gather information about behavior.

4. Longitudinal Studies:

   - Objective: Examine changes in behavior or traits over an extended period.

   - Design: Data collected from the same participants over time to observe developmental changes.

5. Cross-Sectional Studies:

   - Objective: Compare individuals of different ages to assess differences.

   - Design: Data collected from participants of different age groups at a single point in time.

6. Quasi-Experimental Designs:

   - Objective: Investigate cause-and-effect relationships without random assignment.

   - Design: Participants are not randomly assigned to conditions due to ethical or practical reasons.

7. Surveys and Questionnaires:

   - Objective: Gather self-report data on opinions, attitudes, or behaviors.

   - Design: Participants respond to a set of questions, providing quantitative or qualitative data.

8. Naturalistic Observation:

   - Objective: Observe and record behavior in its natural setting.

   - Design: Researchers avoid interfering with the environment, allowing for a more authentic representation of behavior.

9. Case Studies:

   - Objective: In-depth analysis of an individual or small group.

   - Design: Intensive examination of a person's history, behavior, and experiences.

10. Independent and Dependent Variables:

    - Objective: Identify the manipulated and measured aspects in an experiment.

    - Design: The independent variable is manipulated, and the dependent variable is measured to observe the effect.

11. Random Assignment:

    - Objective: Minimize pre-existing differences among participants in different experimental conditions.

    - Design: Participants are randomly assigned to experimental and control groups.

12. Sampling Methods:

    - Objective: Ensure the selected sample is representative of the population.

    - Design: Techniques like random sampling, stratified sampling, or convenience sampling are used.

13. Ethical Considerations:

    - Objective: Ensure the well-being of participants and the integrity of research.

    - Design: Adherence to ethical guidelines, including informed consent, debriefing, and protection from harm.

14. Reliability and Validity:

    - Objective: Assess the consistency and accuracy of measurements.

    - Design: Researchers employ techniques to ensure that data collection methods are reliable and valid.

15. Statistical Analysis:

    - Objective: Draw meaningful conclusions from data.

    - Design: Utilize statistical tests like t-tests, ANOVA, or correlation coefficients to analyze and interpret results.

16. Replication:

    - Objective: Confirm the reliability of study findings.

    - Design: Repeated studies with similar methodologies to ensure the consistency of results.

By mastering these research methods, AP Psychology students can critically evaluate psychological studies, design their own experiments, and contribute to the scientific understanding of behavior and mental processes. Understanding the strengths and limitations of each method is crucial for becoming a proficient consumer and producer of psychological research.

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AP Psychology: Research Methods Notes

Key Takeaways: Research Methods

• The study of psychology relies on a diverse array of qualitative and quantitative research methods, including observations, case studies, surveys, and controlled experiments.
• Psychological research is carefully designed so that researchers can be confident about using results to draw conclusions about real-life phenomena. This is done by controlling variables, creating representative samples, controlling for internal and external validity, and operationalizing definitions and measurements.
• Researchers use statistics to analyze and make sense of the data gathered in a research study. This involves the use of descriptive statistics like measures of central tendency and dispersion, as well as inferential statistics for making generalizations based on the data.
• Because psychological study often involves the participation of human subjects, researchers must abide by established ethical principles and practices as well as legal guidelines while conducting research.

Research Methods Key Terms

Types of psychological research.

• Quantitative research: Research that uses operational measurements and statistical techniques to reach conclusions on the basis of numerical data, such as correlational studies and experiments.
• Qualitative research: Research that does not rely on numerical representations of data, such as naturalistic observations, unstructured interviews, and case studies.
• Correlation coefficient: A number (symbolized by r ) between −1 and +1, which represents the strength and direction of the correlation between two variables. The closer the coefficient is to −1 or +1, the stronger the correlation between the variables.
• Positive correlation: An r value above 0, which indicates that two variables have a direct relationship: when one variable increases, the other also increases.
• Negative correlation: An r value below 0, which indicates that two variables have an inverse relationship: when one variable increases, the other decreases.
• Naturalistic observation: A research method, typically qualitative in nature and usually covert and undisclosed, that attempts to document behavior as it spontaneously occurs in a real world setting.
• Structured observation: A type of observational research typically conducted in a laboratory setting, where the researcher can control some aspects of the environment.
• Coding: The classification of behaviors into discrete categories, used especially in structured observations to achieve a level of consistency in recording and describing observations.
• Inter-rater reliability: A statistical measure of the degree of agreement between different codings of the same phenomena.
• Participant observation: A mostly qualitative research method in which the researcher becomes a member of a studied group, either overtly or covertly.
• Hawthorne effect: A phenomenon in which research subjects tend to alter their behavior in response to knowledge of being observed.
• Longitudinal study: A research design that examines how individuals develop by studying the same sample over a long period of time.
• Cross-sectional study: A research design conducted at a single point in time, comparing groups of differing ages to arrive at conclusions about development.
• Case study: A research design involving an in-depth and detailed examination of a single subject, or case, usually an individual or a small group.
• Survey: A mostly quantitative research method involving a list of questions filled out by a group of people to assess attitudes or opinions.
• Nonresponse bias: A distortion of data that can occur in surveys with a low response rate.
• Surveyor bias: A distortion of data that can occur when survey questions are written in a way that prompts respondents to answer a certain way.
• Experiments: Deliberately designed procedures used to test research hypotheses.
• Hypothesis: A proposed, testable explanation for a phenomenon, often constructed in the form of a statement about the relationship between two or more variables.
• Controlled experiment: A research design for testing a causal hypothesis, in which all aspects of the study are deliberately controlled and only independent variables are manipulated to isolate their effects on dependent variables.
• Field experiment: Experiments conducted out in the real world, with fewer controls than would be found in a lab.

Check out our full Research Methods Notes!

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AP Psychology : Influential Experiments and Methods

Study concepts, example questions & explanations for ap psychology, all ap psychology resources, example questions, example question #1 : influential experiments and methods.

What is the name of the experiments, conducted by Roger Sperry and his colleagues, that revealed the functional specialization of cerebral hemispheres?

Bicameral Mind experiments

Split-Brain experiments

Transcranial Stimulation experiments

Interhemispheric experiments

Lateralus experiments

Roger Sperry and colleagues, using a tachistoscope and other instruments, studied patients that had their corpus callosum severed. Their findings demonstrated that information is specialized in the hemispheres of the brain. 

Example Question #2 : Influential Experiments And Methods

Solomon Asch's line judgment task investigated which phenomenon of human interaction?

Participants in the line-judgment task were asked to identify which of three lines shown in a series of projected images was the longest while sitting in a room with a group of study confederates whom they believed were other participants in the study. The confederates would unanimously agree on the same incorrect line for a question, forcing the participant to choose between conforming to the majority opinion or trusting his/her own eyes and dissenting.

Example Question #3 : Influential Experiments And Methods

During the Milgram Shock Experiment, which of the following factors diminished the likelihood that a participant would obey the commands of the person running the experiment?

All answers are correct

Dressing the experimenter to appear as less of an authority figure

Providing a role model of disobedience

Placing the participant in a different room from the experimenter and relaying instructions via intercom

Placing the participant in the same room as the confederate victim

Participants were more likely to disobey when they were far away from the experimenter or when the experimenter's authority was diminished. They were also more likely to disobey if they were nearer to the suffering victim (really a confederate acting as though they were in pain) or if they had previously observed someone else disobeying.

Example Question #4 : Research And Testing

Which of the following scores represents average intelligence for Terman and Stern's original IQ test?

The IQ test has an average score of 100, with a standard deviation of 15. Scores of 130 or above demonstrate a person with superior ("gifted") intelligence, while scores of 70 or below indicate an intellectual disability. This scale is the same for both the original IQ test, as well as modern iterations.

Example Question #4 : Influential Experiments And Methods

Which famous psychologist studied conformity and obedience by having participants ("teachers") administer electric shocks to other participants ("learners")?

Robert Asch

Phillip Zimbardo

Stanley Milgram

Elizabeth Harwell

Milgram is best known for devising an experiment to study how human participants react when they are asked to shock others. Whenever the "learner" got a memory question wrong, the "teacher" was told to administer a shock to a learner located in a different room. Milgram devised this study to examine how so many people participated in the cruel acts of the Holocaust.

Example Question #5 : Influential Experiments And Methods

Which famous psychological experiment observed infant-caregiver attachment patterns?

Pavlov's Classical Conditioning experiment

Ainsworth's Strange Situation experiment

Zimbardo's Stanford Prison study

Sherif's Robbers Cave experiment

Asch's Conformity study

Mary Ainsworth was a developmental psychologist who is best known for creating the "Strange Situation" to test infant-caregiver attachment patterns. In brief, the Strange Situation involves the caregiver leaving the infant alone for a short period of time, and then returning. Ainsworth observed the infant's response to the caregiver's return, and classified the response into an attachment pattern.

Example Question #6 : Influential Experiments And Methods

Which of the following choices best defines case studies?

Case studies involve one individual and can suggest general principles that may be later applied to a population

Case studies involve one individual and suggest information for only atypical situations. 

Case studies involve one individual and can suggest fruitful ideas

Case studies involve more than one individual and can suggest fruitful ideas

Case studies involve more than one individual and can suggest general principles that may be later applied to all populations

Case studies are known to examine one individual with the ability to collect very detailed data. Despite the hope of being able to reveal information that may later be true for many people, the ideas and suggestions collected from observing one individual cannot be applied to a population. We cannot be sure that observed principles in a particular case can apply or be true for a population—it could be "an exception to the rule.” For instance, a case study may examine one male individual who smokes and has lived to 110; however, a mass study could have been released that suggests the average lifespan for male smokers to be less than 85. In this instance, the case study was of an atypical example; therefore, it would not be scientifically sound to theorize that all male smokers should have a similar life expectancy based on the information of one extraordinary case.

Example Question #3 : History And Research

Which of the following choices best characterizes a research method that collects a mass amount of less in-depth information?

None of these

Counseling 

Naturalistic observation 

Case Study 

Surveys provide the ability to sample multiple cases that require volunteers to self-report their opinions and behaviors. This method permits the statistical analysis of the information collected from a wide variety of participants while also covering a broad base of questioning. Subsequently, surveys are not as keen methods of observation as case studies, naturalistic observation, or counseling. These three methods may require a close engagement with an individual in a particular setting; therefore, they provide an opportunity to collect detailed information about one particular individual as opposed to collecting data on massive populations. 

Example Question #1512 : Ap Psychology

A group of scientists wish to test the relationship between pregnant mothers consuming coconut milk and the intelligence of their children. In order to complete this experiment, what else must the researchers obtain other than a control group?

Experimental group

Double blind study 

Another control group

Blind study

When testing the effects or the relationship between two factors, in this case coconut milk consumption and intelligence, an experiment requires a control and a treatment (experimental) group. The first is the group without the treatment whereas the second is exposed to the treatment (in this case, coconut milk). The two groups should be compared post-experiment after data analysis in order to understand or observe the effects of the treatment relative to standard conditions (in this case, no coconut milk).

Example Question #7 : Influential Experiments And Methods

In Mark Rosenzweig and David Krech's 1950's rat experiment, they observed rats that were in impoverished caged environments versus ones in cages with communally enriched environments that included slides and toys. Which of the following best represent the significant discovery that resulted from the brain analysis of the two types of rats?

The rats from the enriched environments had significant development in all brain tissue

The rats that lived in the enriched environment usually developed a thicker and heavier brain cortex

The rats that lived in confinement developed more neural connections

The rats from the impoverished environment had significant development in all brain tissue

There were no difference between the rats' brains

The result Rosenzweig and colleagues noted was that the brain weight of the environmentally enriched rats increased over time relative to the impoverished rats. Taking a closer look, they realized that it was specifically the cerebral cortex that had the most significantly noticeable difference. This experiment marked a cornerstone in the “nature vs. nurture” debate where genes ("nature") are said to be be responsible for the brain's blueprints, but experiences ("nurture") fill in the rest—in this case, development and establishing impressive branched neural connections. In order to make sure, Rosenzweig and colleagues repeated the experiment multiple times prior to publishing. This finding has been extended into observing the importance of nurturing in early childhood. This was true for the young rats—as seen in the experiment—and has been noted for young children as well. 

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AP Psychology Unit 1 Notes: Scientific Foundations

February 12, 2024.

Get ready for the AP Psychology exam with our free AP Psychology study notes. We've compiled concise unit summaries and key terms and people to jumpstart your AP test prep. These AP Psychology study notes should be used to supplement what you’re learning in your AP Psych class. More study strategies and expert tips can be found in our latest AP Psychology Test Prep Book .

[ READ NEXT: AP Psychology Unit 2 Notes: Biological Bases of Behavior   ]

AP Psychology: Unit 1 Summary

This first unit focuses on the historical origins of the science of psychology, current psychological perspectives, and the research methods psychologists use to gather data about human thinking and behavior. 

History of Psychology

One way to think about the history of psychology is to organize the various theorists and theories into “waves,” or schools of thought. Each wave is a way of thinking about human thought and behavior that dominated the field for a certain period of time until a new way of looking at psychology started to dominate the field. There are five ways: Introspection, Gestalt Psychology, Psychoanalysis, Behaviorism, and Multiple Perspectives.

Different contemporary psychologists look at human thought and behavior from different perspectives. Contemporary perspectives can be placed into eight broad categories: Humanistic, Psychoanalytic, Biopsychology (or Neuroscience), Evolutionary (or Darwinian), Behavioral, Cognitive, Social-Cultural (or Sociocultural), and Biopsychosocial.

Research and Methodology

Psychology is a science, and it is therefore based on research. Though people are often guided effectively by their common intuition, sometimes it leads us astray. People have the tendency upon hearing about research findings (and many other things) to think that they knew it all along; this tendency is called hindsight bias. After an event occurs, it is relatively easy to explain why it happened. The goal of scientific research, however, is to predict what will happen in advance.

An understanding of research methods is fundamental to psychology. Because of that, you are more likely to see a free-response (or essay) question on this topic than on any other. Sometimes psychologists conduct research in order to solve practical problems. For instance, psychologists might compare two different methods of teaching children to read in order to determine which method is better or they could design and test the efficacy of a program to help people quit smoking. This type of research is known as applied research because it has clear, practical applications. Other psychologists conduct basic research. Basic research explores questions that are of interest to psychologists but are not intended to have immediate, real-world applications. Examples of basic research would include studying how people form their attitudes about others and how people in different cultures define intelligence.

Get ahead of the AP game! Our flexible, expert-led AP Psychology Review Course will help you build up your score by breaking down the exam.

Ap psychology: unit 1 key terms & people.

Below, we describe some of the Unit 1 key terms and people you should review ahead of the AP Psychology exam.

• Introspection: The examination of one’s own mental and emotional processes.
• Structuralism: The idea that the mind operates by combining subjective emotions and objective sensations, a theory developed by Wilhelm Wundt.
• Gestalt Psychology: Gestalt psychology tried to examine a person’s total experience because the way we experience the world is more than just an accumulation of various perceptual experiences. Gestalt theorists demonstrated that the whole experience is often more than just the sum of the parts of the experience.
• Sigmund Freud: Freud revolutionized psychology with his psychoanalytic theory. While treating patients for various psychosomatic complaints, Freud believed he discovered the unconscious mind—a part of our mind over which we do not have conscious control that determines, in part, how we think and behave
• Repression: Freud believed that this hidden part of ourselves builds up over the years through repression – the pushing down into the unconscious events and feelings that cause so much anxiety and tension that our conscious mind cannot deal with them.
• Behaviorism: Behaviorists maintain that psychologists should look at only behavior and causes of behavior – stimuli (environmental events) and responses (physical reactions) – and not concern themselves with describing elements of consciousness.
• B.F. Skinner: Another behaviorist, B. F. Skinner expanded the basic ideas of behaviorism to include the idea of reinforcement – environmental stimuli that either encourage or discourage certain responses.
• Eclectic: Currently, there is no one way of thinking about human thought and behavior that all or even most psychologists share. Many psychologists describe themselves as eclectic – drawing from multiple perspectives.
• Humanist Perspective: Humanists stressed individual choice and free will. They believe that we choose most of our behaviors and these choices are guided by physiological, emotional, or spiritual needs.
• Psychoanalytic Perspective: Psychologists using this perspective believe that the unconscious mind – a part of our mind that we do not have conscious control over or access to – controls much of our thought and action. Psychoanalysts would look for impulses or memories pushed into the unconscious mind through repression. This perspective thinks that to understand human thought and behavior, we must examine our unconscious mind through dream analysis, word association, and other psychoanalytic therapy techniques.
• Biopsychology (or Neuroscience) Perspective: Biopsychologists explain human thought and behavior strictly in terms of biological processes. Human cognition and reactions might be caused by effects of our genes, hormones, and neurotransmitters in the brain or by a combination of all three.
• Evolutionary (or Darwinian) Perspective: Evolutionary psychologists (also sometimes called sociobiologists) examine human thoughts and actions in terms of natural selection. Some psychological traits might be advantageous for survival, and these traits would be passed down from the parents to the next generation.
• Behavioral Perspective: Behaviorists explain human thought and behavior in terms of conditioning. Behaviorists look strictly at observable behaviors and human and animal responses to different kinds of stimuli.
• Cognitive Perspective: Cognitive psychologists examine human thought and behavior in terms of how we interpret, process, and remember environmental events. In this perspective, the rules that we use to view the world are important to understanding why we think and behave the way we do.
• Social-Cultural (or Sociocultural) Perspective: Social-cultural psychologists look at how our thoughts and behaviors vary between cultures. They emphasize the influence culture has on the way we think and act. A social-cultural psychologist might explain a person’s tendency to be extroverted by examining his or her culture’s rules about social interaction.
• Biopsychosocial Perspective: This modern perspective acknowledges that human thinking and behavior results from combinations of biological (“bio”), psychological (“psycho”), and social (“social”) factors. Psychologists who emphasize the biopsychosocial perspective view other perspectives as too focused on specific influences on thinking and behavior (sometimes called “being reductionistic”).
• Hindsight bias: People have the tendency upon hearing about research findings (and many other things) to think that they knew it all along; this tendency is called hindsight bias.
• Hypothesis: A hypothesis expresses a relationship between two variables. Variables, by definition, are things that can vary among the participants in the research.
• Theory: A theory aims to explain some phenomenon and allows researchers to generate testable hypotheses with the hope of collecting data that support the theory.
• Valid: Good research is both valid and reliable. Research is valid when it measures what the researcher set out to measure; it is accurate.
• Reliable: Research is reliable when it can be replicated; it is consistent. If the researcher conducted the same research in the same way, the researcher would get similar results.
• Sampling: The individuals on which the research will be conducted are called participants (or subjects), and the process by which participants are selected is called sampling.
• Experiment: Psychologists’ preferred method of research is the experiment because only through a carefully controlled experiment can one show a causal relationship. An experiment allows the researcher to manipulate the independent variable and control for confounding variables.
• Correlation: A correlation expresses a relationship between two variables without ascribing cause. Correlations can be either positive or negative. A positive correlation between two things means that the presence of one thing predicts the presence of the other. A negative correlation means that the presence of one thing predicts the absence of the other.
• Naturalistic observation: Sometimes researchers opt to observe their participants in their natural habitats without interacting with them at all. Such unobtrusive observation is called naturalistic observation. The goal of naturalistic observation is to get a realistic and rich picture of the participants’ behavior. To that end, control is sacrificed.
• Case study method: The case study method is used to get a full, detailed picture of one participant or a small group of participants. While case studies allow researchers to get the richest possible picture of what they are studying, the focus on a single individual or small group means that the findings cannot be generalized to a larger population.
• Descriptive statistics: Descriptive statistics, as the name suggests, simply describe a set of data. For instance, if you were interested in researching what kinds of pets your schoolmates have, you might summarize that data by creating a frequency distribution that would tell you how many students had dogs, cats, zebras, and so on.
• Correlation: A correlation measures the relationship between two variables. Correlations can be either positive or negative.
• Inferential statistics: Whereas descriptive statistics provide a way to summarize information about the sample studied, the purpose of inferential statistics is to determine whether or not findings can be applied to the larger population from which the sample was selected.

Next, test your AP Psychology Unit 1 knowledge using our free Key Terms Worksheets!

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Experimental Design: Types, Examples & Methods

Saul McLeod, PhD

Editor-in-Chief for Simply Psychology

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Saul McLeod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.

Learn about our Editorial Process

Olivia Guy-Evans, MSc

Associate Editor for Simply Psychology

BSc (Hons) Psychology, MSc Psychology of Education

Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.

On This Page:

Experimental design refers to how participants are allocated to different groups in an experiment. Types of design include repeated measures, independent groups, and matched pairs designs.

Probably the most common way to design an experiment in psychology is to divide the participants into two groups, the experimental group and the control group, and then introduce a change to the experimental group, not the control group.

The researcher must decide how he/she will allocate their sample to the different experimental groups.  For example, if there are 10 participants, will all 10 participants participate in both groups (e.g., repeated measures), or will the participants be split in half and take part in only one group each?

Three types of experimental designs are commonly used:

1. Independent Measures

Independent measures design, also known as between-groups , is an experimental design where different participants are used in each condition of the independent variable.  This means that each condition of the experiment includes a different group of participants.

This should be done by random allocation, ensuring that each participant has an equal chance of being assigned to one group.

Independent measures involve using two separate groups of participants, one in each condition. For example:

• Con : More people are needed than with the repeated measures design (i.e., more time-consuming).
• Pro : Avoids order effects (such as practice or fatigue) as people participate in one condition only.  If a person is involved in several conditions, they may become bored, tired, and fed up by the time they come to the second condition or become wise to the requirements of the experiment!
• Con : Differences between participants in the groups may affect results, for example, variations in age, gender, or social background.  These differences are known as participant variables (i.e., a type of extraneous variable ).
• Control : After the participants have been recruited, they should be randomly assigned to their groups. This should ensure the groups are similar, on average (reducing participant variables).

2. Repeated Measures Design

Repeated Measures design is an experimental design where the same participants participate in each independent variable condition.  This means that each experiment condition includes the same group of participants.

Repeated Measures design is also known as within-groups or within-subjects design .

• Pro : As the same participants are used in each condition, participant variables (i.e., individual differences) are reduced.
• Con : There may be order effects. Order effects refer to the order of the conditions affecting the participants’ behavior.  Performance in the second condition may be better because the participants know what to do (i.e., practice effect).  Or their performance might be worse in the second condition because they are tired (i.e., fatigue effect). This limitation can be controlled using counterbalancing.
• Pro : Fewer people are needed as they participate in all conditions (i.e., saves time).
• Control : To combat order effects, the researcher counter-balances the order of the conditions for the participants.  Alternating the order in which participants perform in different conditions of an experiment.

Counterbalancing

Suppose we used a repeated measures design in which all of the participants first learned words in “loud noise” and then learned them in “no noise.”

We expect the participants to learn better in “no noise” because of order effects, such as practice. However, a researcher can control for order effects using counterbalancing.

The sample would be split into two groups: experimental (A) and control (B).  For example, group 1 does ‘A’ then ‘B,’ and group 2 does ‘B’ then ‘A.’ This is to eliminate order effects.

Although order effects occur for each participant, they balance each other out in the results because they occur equally in both groups.

3. Matched Pairs Design

A matched pairs design is an experimental design where pairs of participants are matched in terms of key variables, such as age or socioeconomic status. One member of each pair is then placed into the experimental group and the other member into the control group .

One member of each matched pair must be randomly assigned to the experimental group and the other to the control group.

• Con : If one participant drops out, you lose 2 PPs’ data.
• Pro : Reduces participant variables because the researcher has tried to pair up the participants so that each condition has people with similar abilities and characteristics.
• Con : Very time-consuming trying to find closely matched pairs.
• Pro : It avoids order effects, so counterbalancing is not necessary.
• Con : Impossible to match people exactly unless they are identical twins!
• Control : Members of each pair should be randomly assigned to conditions. However, this does not solve all these problems.

Experimental design refers to how participants are allocated to an experiment’s different conditions (or IV levels). There are three types:

1. Independent measures / between-groups : Different participants are used in each condition of the independent variable.

2. Repeated measures /within groups : The same participants take part in each condition of the independent variable.

3. Matched pairs : Each condition uses different participants, but they are matched in terms of important characteristics, e.g., gender, age, intelligence, etc.

Learning Check

Read about each of the experiments below. For each experiment, identify (1) which experimental design was used; and (2) why the researcher might have used that design.

1 . To compare the effectiveness of two different types of therapy for depression, depressed patients were assigned to receive either cognitive therapy or behavior therapy for a 12-week period.

The researchers attempted to ensure that the patients in the two groups had similar severity of depressed symptoms by administering a standardized test of depression to each participant, then pairing them according to the severity of their symptoms.

2 . To assess the difference in reading comprehension between 7 and 9-year-olds, a researcher recruited each group from a local primary school. They were given the same passage of text to read and then asked a series of questions to assess their understanding.

3 . To assess the effectiveness of two different ways of teaching reading, a group of 5-year-olds was recruited from a primary school. Their level of reading ability was assessed, and then they were taught using scheme one for 20 weeks.

At the end of this period, their reading was reassessed, and a reading improvement score was calculated. They were then taught using scheme two for a further 20 weeks, and another reading improvement score for this period was calculated. The reading improvement scores for each child were then compared.

4 . To assess the effect of the organization on recall, a researcher randomly assigned student volunteers to two conditions.

Condition one attempted to recall a list of words that were organized into meaningful categories; condition two attempted to recall the same words, randomly grouped on the page.

Experiment Terminology

Ecological validity.

The degree to which an investigation represents real-life experiences.

Experimenter effects

These are the ways that the experimenter can accidentally influence the participant through their appearance or behavior.

Demand characteristics

The clues in an experiment lead the participants to think they know what the researcher is looking for (e.g., the experimenter’s body language).

Independent variable (IV)

The variable the experimenter manipulates (i.e., changes) is assumed to have a direct effect on the dependent variable.

Dependent variable (DV)

Variable the experimenter measures. This is the outcome (i.e., the result) of a study.

Extraneous variables (EV)

All variables which are not independent variables but could affect the results (DV) of the experiment. Extraneous variables should be controlled where possible.

Confounding variables

Variable(s) that have affected the results (DV), apart from the IV. A confounding variable could be an extraneous variable that has not been controlled.

Random Allocation

Randomly allocating participants to independent variable conditions means that all participants should have an equal chance of taking part in each condition.

The principle of random allocation is to avoid bias in how the experiment is carried out and limit the effects of participant variables.

Order effects

Changes in participants’ performance due to their repeating the same or similar test more than once. Examples of order effects include:

(i) practice effect: an improvement in performance on a task due to repetition, for example, because of familiarity with the task;

(ii) fatigue effect: a decrease in performance of a task due to repetition, for example, because of boredom or tiredness.

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The Best AP Psychology Notes to Study With

Advanced Placement (AP)

Note-taking can be tricky, even for the most conscientious high school students. It's hard to sort through a whole year's worth of material, especially in an AP class that covers a wide range of topics and theories.

This article is intended to serve as a one-stop shop for comprehensive notes on all the major topics covered in AP Psychology. Whether you lost your class notes on cognition or just want an easier way to see everything in one place, the links in this article will help make your study process more focused and less stressful!

How to Use These AP Psychology Notes

You can use these notes as study aids for in-class tests or to review for the final AP exam . Supplement them with resources you've gotten from your teacher in class and other notes you've taken throughout the year. If you know that there's an especially great explanation of a certain concept in your textbook, use that to help you review as well.

You might also consider buying a review book if you're looking for more guidance in planning out your studying.

If you're studying for the AP test as a whole , take a diagnostic practice test before diving into these notes . That way you can see where you're making the most mistakes and focus your studying on the appropriate areas. Taking practice tests at regular intervals throughout the study process will give you a better idea of whether or not you're absorbing the material.

Real-time practice tests will also help you get used to managing your time effectively so that you're prepared for the way the final exam is structured. You'll be answering 100 multiple-choice questions in 70 minutes, so appropriate pacing is critical!

In the next section, I'll go through a list of all the topics that are covered in AP Psychology and provide links to online notes for each .

AP Psychology Notes to Use in Your Prep

These are the easiest-to-follow online notes I could find for the material covered in AP Psychology. For each topic area, I've included three types of links :

• Regular notes (including section-specific overviews and more general topic outlines)
• Notes accompanied by video resources
• PowerPoint presentations that show the information in a slightly different form

The WikiNotes links are the most detailed , so you should go over those first. The PowerPoints and general topic outlines provide more of a brief overview of concepts and can serve as a quick review tool. If you think you'd benefit from videos, take a look at those resources as well.

It's likely that your AP Psychology course will be structured roughly in the same order as the topics presented here , so it should be easy to find the information you need to study for in-class tests throughout the year. (Note that the Psych topics  changed slightly in 2020 , so the titles of some of the notes you click on may be different than the unit titles, but they still cover the information you need to know.)

Unit 1: Scientific Foundations of Psychology

• General Topic Outline
• Notes With Video Resources

Unit 2: Biological Bases of Behavior

• Neural Processing and the Endocrine System
• Genetics, Evolutionary Psychology, and Behavior

Unit 3: Sensation and Perception

Unit 4: learning, unit 5: cognitive psychology.

• Thinking, Problem Solving, Creativity, and Language
• Notes With Video Resources ( Part 2 )

Unit 6: Developmental Psychology

Unit 7: motivation, emotion, and personality.

• Emotions, Stress, and Health

Unit 8: Clinical Psychology

• WikiNotes 1
• PowerPoint ( Part 1 and Part 2 )
• General Topic Outline 1
• WikiNotes 2
• PowerPoint 2
• General Topic Outline 2
• Notes With Video Resources ( Part 2)

Unit 9: Social Psychology

Overall ap psychology review sheets.

• Full Test Review
• List of Terms and People to Remember
• Interactive Glossary
• AP Psych Cram Sheet
• Psych Review Packet
• AP Psychology Short Review Packet
• AP Psychology Essential Review Sheet

3 Essential AP Psychology Study Strategies

Learning all this information might be tough if you don't have a game plan. Here are some tips for getting the most out of your AP Psychology prep.

#1: Make Friends With Flashcards

To succeed in AP Psychology, you must have excellent recall of a large library of terms. Some of these are constants of human behavior that you didn't know had official names, and others are more obscure terms for the biological components of psychological responses.

It's critical to be fluent in the terminology surrounding every concept if you want to end up with a high score on the AP exam. You should also know the names of prominent psychologists and understand their contributions to the field.

Quizzing yourself with flashcards is the best way to ensure you're prepared. I 'd recommend Quizlet as a starting point (after you read through the notes and refresh your memory) because it offers many sets of online flashcards you can use for practice.

Of course, you can always write out your own physical flashcards if you prefer to do things the old-fashioned way! This might be more effective since writing down definitions helps to reinforce your memory.

#2: Relate Psych Concepts to Everyday Life

The concepts in the AP Psychology course will show up in your daily life when you make decisions, interact socially, get stressed about schoolwork (very meta!), or really do anything.

As you read the notes, try to think of personal examples that relate to what you're learning. Besides helping you memorize the material, doing this can give you some interesting insight into why you've made certain decisions in your life (or why other people you know might have made certain decisions).

Even outside of your active study time, if you notice a particular behavior, try to relate it to something you've learned in AP Psychology. You probably won't forget a term or concept if you anchor it to a real experience.

#3: Give Yourself Regular Checkups

Don't go over a section of AP Psych notes once, quiz yourself, and then decide you're done with it forever. Every few topic areas, circle back and do a holistic review of everything you've learned so far. Make a point of constantly refreshing your memory so that nothing gets lost in the shuffle. You can use the complete AP Psychology review sheets I've linked at the end of the notes section as resources for these review sessions.

Conclusion: Getting the Most Out of AP Psych Notes

These notes and strategies should help you get started on your AP Psychology review. You can even use the notes on a unit-by-unit basis if you're just studying for a short quiz or test. Just remember to take practice tests to keep yourself on track, and continue consulting any resources you've accumulated throughout the year in class.

I recommend also taking advantage of the information in our other AP Psychology guides, such as our ultimate guide and in-depth review , to get more advice on how to structure your studying and to ensure you earn a high score on the final exam!

What's Next?

Are you concerned about the AP Psychology test? Read this article to decide whether it will be especially challenging for you .

What is Stockholm Syndrome, and how is it viewed in psychology circles? Learn more about this condition and its debated legitimacy in this article .

It's not easy to decide which AP classes to take in high school. Depending on how many options you have, you could structure your schedule in vastly different ways. Check out this guide to learn how many AP classes you should take in high school based on your goals and individual circumstances.

If you want to avoid overwhelming yourself with a ridiculous schedule, it's a good idea to be aware of which AP classes test the most challenging material. Read our article on the hardest AP classes here .

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Samantha is a blog content writer for PrepScholar. Her goal is to help students adopt a less stressful view of standardized testing and other academic challenges through her articles. Samantha is also passionate about art and graduated with honors from Dartmouth College as a Studio Art major in 2014. In high school, she earned a 2400 on the SAT, 5's on all seven of her AP tests, and was named a National Merit Scholar.

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AP Psychology Exam Tips

Get to know the questions .

There are two free-response questions for AP Psychology: the Article Analysis Question (AAQ) and the Evidence-Based Question (EBQ).  

• The AAQ gives you 1 summarized peer-reviewed source and asks you to respond to 6 question parts. You’ll analyze the source for the research methods and design elements used, statistics interpretation, ethical guidelines, generalizability, and application of psychological content. 
• The EBQ gives you 3 summarized peer-reviewed sources on a common topic and asks you to respond to 3 question parts. You will propose a claim about the topic and provide 2 pieces of evidence to support your claim. You’ll also explain how the evidence supports your claim and connects to psychological content you learned in the course.  

Look for Task Verbs 

Pay close attention to the task verbs used in the free-response questions. Each one directs you to complete a specific type of response.  

Here are the task verbs you’ll see on the exam: 

• Describe: Provide the relevant characteristics of a specified topic.  
• “Explain how” typically requires analyzing the relationship, process, pattern, position, situation, or outcome;  
• “Explain why” typically requires analysis of motivations or reasons for the relationship, process, pattern, position, situation, or outcome.  
• Identify/State: Indicate or provide information about a specified topic, without elaboration or explanation.  
• Propose: Provide a claim for a specific topic using your own words.  
• Support or Refute: Provide reasoning that explains whether a claim or evidence should be upheld or rejected.  
• Use Evidence: Provide information from a study (i.e., data, rationales, conclusions, hypotheses) that is specific and relevant to a given topic. 

Plan Before You Start Writing 

Answering free-response questions takes training and practice. Students often begin to write immediately, which can create a string of disconnected thoughts. Instead, you should approach questions methodically and plan your answers before responding.  

• Carefully analyze the question, thinking through what is being asked, and identify the elements you’ll need to address in the response. Each AP Exam asks different types of questions. For AP Psychology, you will be asked to read source materials and then use those materials and the knowledge you’ve gained in the course to answer questions. 
• Next, consider what evidence from the source materials you can incorporate into your response. Consider how your evidence is related to content you learned during the year and then decide how it fits into the analysis.  
• Clearly explain why the evidence you use supports the claim or topic you’re referencing and how it connects to the knowledge you gained from the course. Don’t leave it to the reader to infer what you mean or how something illustrates a point.  
• Begin writing only after you have thought through the evidence you plan to use and determined what your argument will be. Once you’ve done this, you will be able to answer the question clearly. 

Practice Before Exam Day 

You may wish to work specifically on the free-response questions available in AP Classroom and on AP Central. Review the scoring rubrics for the questions to understand how the answers are scored. Sample responses for each point category are included in each scoring rubric. 

AP Classroom Resources

Once you join your AP class section online, you’ll be able to access AP Daily videos, any assignments from your teacher, and your assignment results in AP Classroom. Sign in to access them.

• Go to AP Classroom

Free-Response Questions and Scoring Information

Go to AP Central to view free-response questions and scoring information from past exams.

AP Psychology Course and Exam Description

This is the core document for the course. It clearly lays out the course content and describes the exam and AP Program in general.

AP Psychology Exam Questions

Free-response questions and scoring information.

Download free-response questions from past exams along with scoring guidelines, sample responses from exam takers, and scoring distributions.

If you are using assistive technology and need help accessing these PDFs in another format, contact Services for Students with Disabilities at 212-713-8333 or by email at [email protected] .

In light of the 2024-25 AP Psychology course and exam revisions , the questions and scoring information on this page do not completely align with the current AP Psychology Exam. We’re keeping these older questions available because AP teachers have told us that even imperfectly aligned questions can still be valuable instructional resources. 

2024: Free Response Questions

2024: free-response questions.

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2020: Free-Response Questions

The 2020 free-response questions are available in the  AP Classroom question bank .

2019: Free-Response Questions

2018: Free-Response Questions

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2016: Free-Response Questions

2015: Free-Response Questions

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That actually explain what's on your next test, experiments, from class:, ap psychology.

Experiments are a type of research method where the researcher manipulates one variable (independent variable) to determine its effect on another variable (dependent variable).

congrats on reading the definition of Experiments . now let's actually learn it.

Related terms

Control Group : In an experiment, this is the group that does not receive the treatment or manipulation so it can serve as a comparison against the experimental group.

Experimental Group : This is the group that receives the treatment or manipulation in an experiment.

Random Assignment : A procedure in conducting experiments where each participant has an equal chance of being assigned to any group. It’s like drawing names from a hat to decide who gets which treatment.

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Practice Questions ( 6 )

• Which of the following experiments would best test the hypothesis that sleep deprivation disrupts the consolidation of long-term memories?
• Which principle ensures that psychologists do not harm their clients during treatment or experiments?
• How does the principle of informed consent apply to experiments on perception?
• How can psychologists avoid harm to clients during therapy or experiments?
• Which of the following experiments would provide the best testing of the James-Lange theory of emotions?
• What ethical considerations would psychologists have to take into account when interpreting data from experiments on neural firing?

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AP® Psychology

11 tough vocab terms for ap® psychology research methods.

• The Albert Team
• Last Updated On: March 1, 2022

The AP® Psychology research methods is one of the most term heavy topics within AP® Psychology. Being able to differentiate between the terms will benefit you on your exam and reduce confusion once you begin running experiments.

1. Operational Definition

The operational definition is a term that is used to describe the procedure of a study and the research variables. When thinking about the operational definition, it is beneficial to visualize what the experiment is measuring and how it is going to be measured.

An example of this would be an experiment that is measuring if Timmy laughs more at girls or boys. The operation definition of this experiment would say what the experiment defines as a laugh. This experiment may operationally define a laugh as a smile with a sound.

By having this operational definition, other psychologists are able to replicate the experiment. The operational definition lets the reader of the experiment know what was deemed a positive or negative result, thereby opening the experiment up for replication and expansion by other psychologists.

2. Random Sample

A random sample is when the group of subjects in your experiment accurately depicts the population. This random sample should fairly depict the overall population, covering various ethnicities, socioeconomic classes, gender, and age.

An example of this would be if we use Timmy’s study again. To have a truly random sampling of people we must get a population of girls and boys that represent all of the different types of people. We would need all races and socioeconomic groups as well as ages. The random sampling also dictates that the experimenter must have little to no bias in choosing the people in the sample. It is advised to choose the participants in an impartial way to retain random sampling. One way that this is often done is by taking every third person in a given population for the study.

3. Random Assignment

Random assignment is different than random sampling in that random sampling deals with choosing who participates in the study. Random assignment, however, dictates which of the selected experimental population will go to the control group or the experimental trial.

This is important, because random assignment keeps the person running the experiment from putting people that he or she thinks will be affected into the experimental group. By randomly assigning people to each group, then the experiment retains validity.

An example of this would be placing a random half of the random sampling, or the selected population, into a placebo group and the other half into the experimental group for a drug trial.

4. Correlation Coefficient

The correlation coefficient is a number that lies between negative one (-1) and positive one (+1). This number represents how close to cause and effect the experiment is. The number one represents that perfect cause and effect in a positive direction and the negative one represents perfect cause and effect in the negative direction.

The experiment usually does not work out to be perfect, making the correlation coefficient a decimal. The close the decimal is to one dictates the strength of the correlation. For example, if .78 was the correlation coefficient, then the strength of the cause and effect would be much higher than .34 correlation. This can be seen pictured to the left.

It is important, however, to note that correlation does not directly make causation. This means that just because something has a strong correlation, it does not mean that the same outcome will always be caused by the independent variable.

5. Illusory Correlation

The illusory correlation is a phenomenon that psychologists must avoid during experimentation. This correlation is when the person believes that a relationship exists between two variables when it does not.

A great example of this are some superstitions like an unwashed, favorite jersey will lead to a win for a sports team. There is not actual relationship between a fan wearing and not washing a jersey and winning the game, but that fan believes that there is.

6. Dependent Variable

The dependent variable is the variable that measures the outcome of the experiment. This is the response. For example, if we are measuring which comedian makes the children laugh, then we will be measuring how many times the children laugh for the dependent variable.

The experimenter should have no influence on what dependent variable takes place; otherwise this would be a skewed test.

7. Independent Variable

The independent variable is what causes the dependent variable. This independent variable would be the comedian in the case of recording the funniest comedian to children. The comedian causes the laughter, which is the dependent variable, making that comedian or comedians the independent variable.

The independent variable must be influenced by the experimenter, because this psychologist must craft the independent variable so that other variables do not influence the dependent variable. To do so would mean that the experiment contains error.

A great way to control the independent variable and the experiment as a whole is by utilizing random sampling and random assignment.

8. Confounding Variable

The confounding variable is the variable that is often referred to as the extraneous variable. This variable is unwanted in the experiment, although the confounding variable unfortunately ends up in many experiments unintentionally. The confounding variable is a variable that the experimenter did not account for initially that affected the dependent variable. For example, the random sampling may result in not so random sample. If the random sample contained mostly one social class and it affected the experiment’s outcome, then that would be the confounding variable.

If the confounding variable is too influential towards the dependent variable, then the experiment could be deemed invalid.

9. Standard Deviation

Standard deviation is a statistical procedure that is done in order to determine how far away from the average result. The standard deviation is a way for the experimenter to tell how much variation is in the results. As the standard deviation gets higher, the more variation is occurring in the data.

For the AP® Psychology exam it is important to know the percentage of the population that occupies one standard deviation, which is sixty-eight percent, and two standard deviations, which is ninety-five percent. The other five percent are within three standard deviations. This can be seen in the bell shaped curve pictured to the right.

10. The Double Blind Procedure

The double blind procedure is when neither the participant in the study nor the person giving the study know who is the control group and who is in the experimental group. This allows the study to detect the Placebo Effect. The Placebo Effect is when a group of people feel an effect of a drug when they have actually only ingested a placebo, which is often a sugar pill that has no effect.

The double blind procedure keeps as much bias out of the procedure as possible, allowing the psychologists doing the procedure to more accurately determine if the result is accurate.

11. Internal Validity

Internal validity is a term that represents the confidence that can be put into the experiment’s results. For an experiment to have internal validity, then all of the confounding variables must have been acknowledged and controlled by the experimenter. Also, there must be a relationship statistically between the independent variable and the dependent variable for internal validity.

Key Takeaway for AP® Psychology

These eleven terms on the research methods portion of AP® Psychology may seem unneeded or common sense; however, in order to construct a more reliable experiment with internal validity one must be wary of them all during experiment crafting.

By being able to pick out parts of an experiment and tell why an experiment is valid or invalid is also a large part of many of the free response questions. Being able to do this will be sure to boost your score on exam day.

Let’s put everything into practice. Try this AP® Psychology practice question:

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Check out our other articles on  AP® Psychology .

You can also find thousands of practice questions on Albert.io. Albert.io lets you customize your learning experience to target practice where you need the most help. We’ll give you challenging practice questions to help you achieve mastery of AP Psychology.

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Cognitive Psychology Experiments: Unveiling the Mysteries of the Mind

From illusions that deceive our senses to the limits of our memory, cognitive psychology experiments have long sought to unravel the enigmatic workings of the human mind. Our brains, these marvelous biological computers, continue to baffle and amaze us with their complexity and capabilities. Yet, through the tireless efforts of researchers and the ingenious design of experiments, we’ve managed to peek behind the curtain of consciousness and glimpse the inner workings of our cognitive processes.

Cognitive psychology, the study of mental processes such as attention, language use, memory, perception, problem-solving, creativity, and thinking, has been at the forefront of this exploration. It’s a field that bridges the gap between our subjective experiences and the objective world of scientific inquiry. By designing clever experiments, cognitive psychologists have managed to shine a light on the hidden mechanisms that drive our thoughts, decisions, and behaviors.

The journey of cognitive psychology began in the mid-20th century, emerging as a response to the limitations of behaviorism. While behaviorists focused solely on observable behaviors, cognitive psychologists argued that to truly understand the human mind, we needed to examine the internal mental processes that give rise to those behaviors. This shift in perspective opened up a whole new world of research possibilities, leading to a boom in experimental studies that continue to shape our understanding of the mind to this day.

The significance of these experiments cannot be overstated. They’ve not only advanced our theoretical understanding of cognition but have also had profound practical implications. From improving educational methods to developing more effective therapies for mental health disorders, the insights gained from cognitive psychology experiments have touched nearly every aspect of our lives.

Foundational Cognitive Psychology Experiments: The Building Blocks of Understanding

Let’s kick things off with a colorful conundrum that’s been puzzling psychologists for decades: the Stroop Effect. Imagine you’re presented with a list of color words, but here’s the catch – the words are printed in different colors than what they spell. For instance, the word “RED” might be printed in blue ink. Your task? Simply name the color of the ink, not read the word. Sounds easy, right? Well, prepare to have your mind blown!

Most people find this task surprisingly difficult, often stumbling and slowing down when the word and ink color don’t match. This phenomenon, first described by John Ridley Stroop in 1935, reveals the powerful interference between our automatic reading processes and our ability to name colors. It’s a prime example of how our cognitive processes can sometimes trip us up, even in seemingly simple tasks.

But wait, there’s more! Let’s take a stroll down memory lane with George Miller’s “Magic Number” experiment. In 1956, Miller proposed that our short-term memory capacity is limited to about seven items, plus or minus two. He arrived at this conclusion after presenting participants with lists of random items (like digits, letters, or words) and asking them to recall as many as possible.

Surprisingly, most people could remember about seven items, regardless of whether they were simple digits or complex concepts. This “magic number” has had far-reaching implications, influencing everything from the design of phone numbers to the way we organize information in user interfaces. It’s a testament to how a single, well-designed experiment can reshape our understanding of human cognition and impact our daily lives.

Now, let’s dive into the murky waters of memory reconstruction with Elizabeth Loftus and John Palmer’s groundbreaking work on eyewitness testimony. In their famous 1974 experiment, participants watched videos of car accidents and were then asked questions about what they saw. Here’s where it gets interesting: the researchers found that simply changing the wording of the questions could alter the participants’ memories of the event.

For instance, when asked “How fast were the cars going when they smashed into each other?”, participants estimated higher speeds than when the word “smashed” was replaced with “hit” or “contacted”. Even more astonishingly, a week later, participants who had been asked about the cars “smashing” were more likely to falsely remember seeing broken glass in the video – even though there was none!

This experiment sent shockwaves through the legal system, challenging the reliability of eyewitness testimony and highlighting the malleability of human memory. It’s a stark reminder that our memories aren’t perfect recordings of past events, but rather reconstructions that can be influenced by subsequent information and the way questions are phrased.

Attention and Perception Studies: The Invisible Gorilla and Other Mind-Bending Phenomena

Now, let’s turn our attention to… well, attention itself! One of the most jaw-dropping demonstrations of selective attention comes from Daniel Simons and Christopher Chabris’ “Gorilla in our midst” experiment. Picture this: you’re watching a video of people passing a basketball, and your task is to count the number of passes made by one team. Sounds simple enough, right? But here’s the kicker – in the middle of the video, a person in a gorilla suit walks right through the scene, beats their chest, and exits.

You’d think everyone would notice a gorilla, wouldn’t you? Surprisingly, about half of the participants in this experiment were so focused on counting passes that they completely missed the gorilla! This phenomenon, known as inattentional blindness, shows just how selective our attention can be. It’s a humbling reminder that we often see what we’re looking for and miss what we’re not expecting, even when it’s right in front of our eyes.

Speaking of missing things right in front of our eyes, let’s talk about change blindness. This phenomenon occurs when we fail to notice changes in our visual environment, even when they’re quite significant. In one famous demonstration, researchers showed participants alternating images of two people having a conversation. The images were identical except for one major change – in one image, the first person wore a hat, and in the other, they didn’t.

Astonishingly, many participants failed to notice this change, even after multiple viewings. This experiment highlights the limitations of our visual awareness and challenges our intuitive belief that we see and remember everything in our environment. It’s a sobering thought that we might be missing more of the world around us than we realize!

Lastly, let’s explore the world of visual search with Anne Treisman’s Feature Integration Theory experiments. Treisman proposed that our visual perception occurs in two stages: a pre-attentive stage where we process basic features like color and shape in parallel, and a focused attention stage where we combine these features into coherent objects.

To test this theory, Treisman conducted experiments where participants had to find a target item among distractors. She found that when the target differed from distractors in a single feature (like a red circle among blue circles), people could find it quickly regardless of the number of distractors. However, when the target was defined by a combination of features (like a red circle among blue circles and red squares), search times increased with the number of distractors.

These findings have had profound implications for our understanding of visual perception and attention. They’ve influenced everything from the design of user interfaces to strategies for improving visual search in real-world scenarios like airport security screenings.

Memory and Learning Experiments: Forgetting Curves and Spaced Repetition

Let’s take a journey back to the late 19th century, where Hermann Ebbinghaus was busy memorizing nonsense syllables. Why, you ask? Well, Ebbinghaus was on a mission to understand how our memory works, particularly how we forget information over time. His painstaking self-experiments led to the discovery of the “forgetting curve” – a graph showing how information is lost over time when there’s no attempt to actively recall it.

Ebbinghaus found that memory loss is rapid at first, but then levels off. For instance, he might forget 50% of the nonsense syllables within an hour, but then only forget another 10% over the next month. This insight has had profound implications for learning and education. It’s why cramming the night before an exam isn’t as effective as spaced repetition – reviewing material at gradually increasing intervals.

Speaking of context, let’s dive into the fascinating world of the Encoding Specificity Principle, brought to us by Endel Tulving and Donald Thomson. Their experiments showed that the context in which we learn information plays a crucial role in our ability to recall it later. In one study, participants learned lists of words either on dry land or underwater. Surprisingly, they were better at recalling the words in the same environment where they learned them.

This principle extends beyond physical environments to emotional states and even physiological conditions. Ever had trouble remembering something you knew you knew, only to have it pop into your head later in a different context? That’s the Encoding Specificity Principle at work! It’s a reminder that memory isn’t just about storing information, but about creating rich, contextual associations that aid in retrieval.

Now, let’s talk about a learning phenomenon that’s music to the ears of procrastinators everywhere – the Spacing Effect. This effect, first discovered by Hermann Ebbinghaus (yes, him again!) and later elaborated by many others, shows that we learn more effectively when we space out our study sessions over time, rather than cramming everything into one marathon session.

In a typical experiment demonstrating this effect, participants might be asked to learn a list of words. One group studies the list in a single session, while another group studies it in multiple shorter sessions spread out over time. When tested later, the spaced-learning group almost always outperforms the cramming group, even when the total study time is the same.

This finding has revolutionary implications for education and learning. It suggests that shorter, more frequent study sessions are more effective than longer, less frequent ones. So, the next time you’re tempted to pull an all-nighter before a big exam, remember – your brain might thank you for spreading out your study sessions instead!

Decision-Making and Problem-Solving Studies: Logic, Framing, and Functional Fixedness

Let’s kick off this section with a brain-teaser that’s stumped countless participants – the Wason Selection Task. Imagine you’re shown four cards. You know that each card has a letter on one side and a number on the other. The visible faces of the cards show A, D, 4, and 7. Now, you’re told there’s a rule: “If a card has a vowel on one side, then it has an even number on the other side.” Your task? Select only the cards you need to turn over to check if the rule is being followed.

Sounds simple, right? Well, prepare to have your mind boggled! Most people choose A and 4, but the correct answer is A and 7. This task, developed by Peter Wason in 1966, reveals our struggles with abstract logical reasoning. It’s a stark reminder that our brains aren’t naturally wired for formal logic, and that we often rely on intuitive shortcuts that can lead us astray.

Now, let’s shift gears to a phenomenon that’s shaped our understanding of decision-making – the Framing Effect. This cognitive bias, explored in depth by Amos Tversky and Daniel Kahneman, shows how the way information is presented (or “framed”) can dramatically influence our choices.

In one classic experiment, participants were presented with a hypothetical scenario where 600 people were at risk from a disease outbreak. They were then given two treatment options:

– Option A: “200 people will be saved” – Option B: “There’s a 1/3 probability that 600 people will be saved, and a 2/3 probability that no one will be saved”

Interestingly, most people chose Option A. But when the same scenario was presented with different framing:

– Option C: “400 people will die” – Option D: “There’s a 1/3 probability that nobody will die, and a 2/3 probability that 600 people will die”

Suddenly, most people preferred Option D, even though it’s mathematically equivalent to Option B!

This experiment reveals how our decisions can be swayed by the way information is presented, even when the underlying facts remain the same. It’s a sobering reminder of how susceptible we are to manipulation through framing, with implications ranging from marketing strategies to public health communications.

Lastly, let’s shine a light on a cognitive quirk that can hinder our problem-solving abilities – functional fixedness. This phenomenon was beautifully illustrated by Karl Duncker’s Candle Problem. In this experiment, participants were given a candle, a box of thumbtacks, and a book of matches. Their task? Attach the candle to the wall so that it can burn properly without dripping wax on the table below.

Many participants struggled with this task, trying to tack the candle directly to the wall or melt some of the wax to stick it. The solution, however, was to empty the box of thumbtacks, tack the box to the wall, and use it as a platform for the candle. The difficulty arose because people were fixated on the box’s function as a container for thumbtacks, failing to see its potential as a candleholder.

This experiment reveals how our preconceived notions about an object’s function can limit our problem-solving abilities. It’s a reminder to think outside the box – sometimes quite literally! – when faced with challenging problems.

Modern Cognitive Psychology Experiments: Peering into the Brain and Beyond

As we venture into the 21st century, cognitive psychology has embraced new technologies and methodologies, opening up exciting new avenues for research. One of the most revolutionary developments has been the advent of neuroimaging studies, which allow us to peek inside the brain as it performs various cognitive tasks.

Functional Magnetic Resonance Imaging (fMRI) studies, for instance, have allowed researchers to observe which areas of the brain “light up” during different cognitive processes. In one fascinating experiment, participants were asked to imagine walking through their homes while their brains were being scanned. The researchers found that different areas of the brain activated in sequence, corresponding to the mental “walk” through different rooms. This kind of study provides unprecedented insights into how our brains represent and navigate spatial information.

But it’s not just about pretty brain pictures. These neuroimaging studies have practical applications too. For example, they’ve been used to study the neural basis of cognitive biases, helping us understand why we’re prone to certain systematic errors in thinking. One study used fMRI to examine the brain activity of participants as they made financial decisions. The researchers found that when people experienced the “sunk cost fallacy” – continuing to invest in a failing project because of past investments – there was increased activity in areas of the brain associated with negative emotions and conflict resolution.

Speaking of cognitive biases, modern cognitive psychology has continued to uncover and explore these fascinating quirks of human thinking. One particularly intriguing area of research has been the study of the “Dunning-Kruger effect” – the tendency for people with low ability in a specific domain to overestimate their competence.

In a series of experiments, Justin Kruger and David Dunning asked participants to rate their abilities in various domains (like logical reasoning or grammar) and then tested their actual performance. They found that those who performed poorly on the tests consistently overestimated their abilities, while high performers tended to underestimate theirs. This effect has profound implications for everything from education to workplace dynamics, highlighting the importance of self-awareness and continuous learning.

Lastly, let’s talk about a hot topic in modern cognitive psychology – multitasking. In our hyper-connected world, many of us pride ourselves on our ability to juggle multiple tasks simultaneously. But what does the research say about the effects of multitasking on our attention and performance?

One eye-opening study by Eyal Ophir, Clifford Nass, and Anthony Wagner compared the cognitive abilities of heavy media multitaskers (people who frequently use multiple media simultaneously) with those of light media multitaskers. Contrary to what many might expect, they found that heavy multitaskers performed worse on tasks that required switching between different types of information. They were more easily distracted by irrelevant information and had more difficulty organizing their memories.

This research challenges the common belief that multitasking makes us more efficient. Instead, it suggests that constantly dividing our attention might be impairing our ability to focus and process information effectively. It’s a sobering thought in an age where we’re constantly bombarded with information from multiple sources.

As we wrap up our whirlwind tour of cognitive psychology experiments, it’s clear that this field has come a long way since its inception. From the foundational studies that shaped our understanding of attention, memory, and perception, to the cutting-edge research using neuroimaging and exploring cognitive biases, each experiment has added a piece to the puzzle of the human mind.

These studies have not only advanced our theoretical understanding but have also had profound practical implications. They’ve influenced educational practices, shaped legal procedures, informed design principles, and even changed how we think about our own thinking. The insights gained from cognitive psychology experiments have truly permeated every aspect of our lives.

As we look to the future, the field of cognitive psychology continues to evolve. Emerging technologies like virtual reality and artificial intelligence are opening up new possibilities for experimental design and data analysis. At the same time, there’s a growing recognition of the need for more diverse and representative participant pools to ensure that our understanding of cognition isn’t limited to a narrow subset of humanity.

One thing is certain – the human mind remains as fascinating and mysterious as ever. As we continue to probe its depths through clever experiments and rigorous analysis, we’re sure to uncover even more surprises. Who knows? The next groundbreaking cognitive psychology experiment might be just around the corner, ready to revolutionize our understanding of the mind once again.

So, the next time you find yourself marveling at the quirks of your own thinking – whether you’re struggling to ignore the word “RED” written in blue ink, or wondering how you missed that gorilla in the basketball game – remember that you’re experiencing firsthand the phenomena that cognitive psychologists have been studying for decades. Our minds may be enigmatic, but with each experiment, we get a little closer to unraveling their mysteries.

References:

1. Stroop, J. R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18(6), 643-662.

2. Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63(2), 81-97.

3. Loftus, E. F., & Palmer, J. C. (1974). Reconstruction of automobile destruction: An example of the interaction between language and memory. Journal of Verbal Learning and Verbal Behavior, 13(5), 585-589.

4. Simons, D. J., & Chabris, C. F. (1999). Gorillas in our midst: Sustained inattentional blindness for dynamic events. Perception, 28(9), 1059-1074.

5. Treisman, A. M., & Gelade, G. (1980). A feature-integration theory of attention. Cognitive Psychology, 12(1), 97-136.

6. Ebbinghaus, H. (1885/1913). Memory: A contribution to experimental psychology. New York: Teachers College, Columbia University.

7. Tulving, E., & Thomson, D. M. (1973). Encoding specificity and retrieval processes in episodic memory. Psychological Review, 80(5), 352-373.

8. Wason, P. C. (1966). Reasoning. In B. M. Foss (Ed.), New horizons in psychology. Harmondsworth: Penguin.

9. Tversky, A., & Kahneman, D. (1981). The framing of decisions and the psychology of choice. Science, 211(4481), 453-458.

10. Duncker, K. (1945). On problem-solving. Psychological Monographs, 58(5), i-113.

11. Kruger, J., & Dunning, D. (1999). Unskilled and unaware of it: How difficulties in recognizing one’s own incompetence lead to inflated self-assessments. Journal of Personality and Social Psychology, 77(6), 1121-1134.

12. Ophir, E., Nass, C., & Wagner, A. D. (2009). Cognitive control in media multitaskers. Proceedings of the National Academy of Sciences, 106(37), 15583-15587.

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