Barron's 2025 AP Psychology Unit 2: Research Methods

Hindsight Bias

belief that an outcome was easily predictable after it occured

Conformation Bias

Bias that causes on to pay more attention to findings that support their belief.

Overconfidence

Extra/excessive faith in ones own beliefs

Applied Research

Research conducted to solve practical problems. ex) efficacy of anti-smoking program

Basic Research

Questions that interest psychologists but don’t have real world applications. ex) how ppl in diff. cultures define. intelligence.

Quantitative Research

Uses numerical data

Qualitative Research

Uses more complex textual responses and key themes w/in them.

Hypothesis

Explains the relation b/w 2 variables

Variables

Things that can vary among participants in the research. ex) height, weight, religion, stress lvl

Independent Variable

The variable that is manipulated or changed in an experiment to observe its effects on the dependent variable.

Dependent Variable

The variable that is measured in an experiment to determine the effects of the independent variable.

Theory

Aims to explain some phenomenon and allow researchers to generate testable hypotheses.

Falsifiable

Characteristic of hypothesis or theory that allows for a possibility that it may be wrong

Operational definitions (operationalize)

Specific explanations of abstract concepts or variables that clarify how they will be measured or manipulated in a study. ex) what behaviors will be considered aggressive?

Raises issues abt reliably/validity of research.

Replicated research

Studies that are repeated to determine if findings are consistent and reliable.

Subjects/participants

Indivs on whom the research will be conducted.

Sampling

Process in which subjects are chosen

Sample

A group of participants

Population

Anyone/anything that could be possibly selected to be in the sample

Representative Sampling

Selection of subjects who are representative of whole population.

ex)only polling incarcerated Jews trying to find out how much religion contributes to violence.

Larger and more diverse groups of subjects are more representive

Random Sampling

when every indiv. of a pop. has an equal chance of being selected.

Increases the likelyhood that the sample is a good representation of the whole pop.

Only way sample can be truly random is by having a computer select, selectinging numbers as a placeholder for names, picking names out of a hat

Genralize

The ability to take findings from a sample and apply them to a larger population

Convenience Sampling

Collecting data from a group of ppl who are easily accessible to you. ex) using friends/family, or ppl at your work.

Stratified sampling

process that allows researchers to ensure the sample represents the population. ex) If 500/1000 ppl are school are white, 300 are black, and 200 are indian; have 50 white students, 30 black, and 20 Indian represented.

Way of doing that would be to subdivide potential participants and randomly select from a specific group to fill that quota.

Lab experiment

Exp. conducted in a lab and is very controlled

Field exp.

Exp. done out in the world, making them less controlled but more realistic.

Experiment

Shows causal relationship.

Psychologists preferred method of research.

Allows for researchers to manipulate independent var. and control for confounding variables.

Confounding variables

Factors other than the independent variable that could affect the dependent variable in an experiment.

Makes it difficult to determine the true cause-and-effect relationship.

Assignment

Process in which subjects are placed into groups (control or exp.)

Random Assignment

Each subject has a chance or being placed in either group.

Limits the effect of subject-relevant confounding variables

Experimenter Bias

Unconscious tendency for researchers to treat members of groups diff. to prove their hypothesis correct.

Situation-relevant confounding variable

Double blind study

When neither the participants or the researcher are able to affect the outcome of the research. neither the participants nor the researchers know who is in the experimental group and who is in the control group

Single blind study

When the participants do not know whether they are in the experimental or control group, but the researchers are aware of group assignments. This helps prevent participant bias, such as the placebo effect.

Social desirability bias

The tendency to choose answers that make one look good

Exp. group

The group that gets treatment operationalized in the independent var.

Control group

group w/o independent var.

serves as a basis for comparison

Placebo method

A fake treatment given to a control group to separate the effects of the treatment from a participant's belief in the treatment.

ex) giving sugar pill instead of drug

Placebo effect

A fake treatment used to see if an experimental outcome is due to the actual treatment or a participant's belief in it.

Positive Correlation

When the presence of one thing predicts the presence of another.

Negative Correlation

When the presence of one thing predicts the absence of another.

ex post facto(quasi experimental) study

When the independent variable is not manipulated by the researcher but has already occurred naturally.

The effects of the pre-existing condition on a dependent variable is examined.

Because participants are not randomly assigned to groups, it helps describe relationships but cannot establish a definitive cause-and-effect relationship.

ex) studying the academic performance of students who attended a specific pre-school program versus those who did not, where the program attendance was not controlled by the researchers.

Survey method

Research design where ppl fill out surveys.

May include likert scales

Shows if there is or isn’t correlation between 2 variables, but not which is the cause or the effect. ex) group of people surveyed plays video games and has been arrested. no cause/effect

likert scales

Pose a statement and ask the subject to agree or disagree.

Correlation

Expresses a relationship b/w variables without ascribing a cause.

Directionality problem/ temporal variance

The inability to tell which variable came first

Third Variable

When an unknown variable is causing the effect, rather than the watched variable

Leads to a spurious (false) correlation

Naturalistic Observation

When participants are observed in their natural habitat w/o researchers interacting w/ them.

Most realistic outcome

Causes lack of control

Structured interview

When all subjects are asked the exact same set of predetermined questions in a specific order.

Ensures consistency across interviews, making it easier to compare responses and gather reliable data.

Qualitative NOT quantitative

ex) a teacher gathering feedback from students might ask every student the exact same five predetermined questions about the course material in the same sequence.

Case study

Used to get a full, detailed picture of 1 participant or a small group of participants.

ex) clinicians present case studies abt ppl w/ a spec. disease.