AP Psych Unit 0 Vocabulary

Critical Thinking

thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions.

Hindsight Bias

the tendency to believe, after learning an outcome, that one would have foreseen it

illusory correlation

perceiving a relationship where none exists, or perceiving a stronger-than-actual relationship

Peer Reviewers

scientific experts who evaluate a research article's theory, originality, and accuracy

Theory

A broad explanation that organizes observations and predicts outcomes.

Hypothesis

A testable prediction, often implied by a theory

Falsifiable

able to be disproven by experimental results

Operational Definition

A clear, measurable definition of a variable (specifying exactly how it will be measured or manipulated).

Replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances

Case study

an observation technique in which one person is studied in depth in the hope of revealing universal principles

Naturalistic Observation

observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

Survey

a technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group

Social Desirability Bias

A tendency to give socially approved answers to questions about oneself.

Self-Report Bias

Problems that occur when people respond with socially desirable responses

Sampling Bias

a flawed sampling process that produces an unrepresentative sample

Random Sampling

a sample that fairly represents a population because each member has an equal chance of inclusion

Population

A group of individuals that belong to the same species and live in the same area

Correlation

A measure of how strongly two variables vary together; useful for prediction but cannot establish cause-and-effect.

correlation coefficient

a statistical index of the relationship between two things (from -1 to +1)

Variable

A factor that can change in an experiment

Scatterplot

a graphed cluster of dots, each of which represents the values of two variables

Regression towards the mean

the tendency for extreme or unusual scores to fall back (regress) toward their average.

Experiment

A method that manipulates an independent variable (IV) and measures its effect on a dependent variable (DV) while controlling other factors; best for establishing causation.

Experimental Group

In an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable.

Control Group

In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

Random Assignment

assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups

Single-blind procedure

research design in which participants don't know whether they are in the experimental or control group

Double-blind procedure

an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies.

Placebo effect

the phenomenon in which the expectations of the participants in a study can influence their behavior

Independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

Confounding variable

a factor other than the independent variable that might produce an effect in an experiment

Experiment bias

the unconscious tendency for researchers to treat members of the experimental and control groups differently to increase the chance of confirming their hypothesis

Dependent variable

The outcome factor; the variable that may change in response to manipulations of the independent variable.

Validity

the extent to which a test measures or predicts what it is supposed to

Quantitative Research

research that collects and reports data primarily in numerical form

Qualitative research

research that relies on what is seen in field or naturalistic settings more than on statistical data

Psychology

Psychology is the scientific study of behavior (what organisms do) and mental processes (how organisms think, feel, perceive, and remember).

Wilhelm Wundt

Founder of the first psychology laboratory (Leipzig, 1879); helped establish psychology as a field that studies the mind systematically.

Introspection

Early method in which trained participants reported their conscious experiences; important historically but limited because reports are subjective and hard to verify.

Structuralism

aimed to describe the basic “elements” of conscious experience (like the building blocks of perception).

Functionalism

focused on what mental processes and behaviors do—how they help an organism adapt, survive, and flourish.

Behaviorism

Perspective arguing psychology should focus on observable behavior and how the environment shapes learning, emphasizing measurable variables and strong experimental design.

Psychoanalytic perspective

(associated with Freud) emphasized unconscious influences and early childhood experiences.

Humanistic perspective

emphasized growth, meaning, and personal agency.

Cognitive approach

Approach that studies mental processes such as attention, memory, language, and problem-solving.

Biological approach

Approach explaining behavior and mental processes in terms of the brain, nervous system, hormones, and genetics.

evolutionary approach

asks how behaviors and mental traits might have been shaped by natural selection.

Sociocultural approach

emphasizes how social contexts and cultural norms shape behavior and thinking.

Biopsychosocial approach

Framework viewing behavior as the product of interacting biological, psychological, and social-cultural influences.

Hawthorne effect (reactivity)

A change in behavior that occurs because people know they are being observed.

Representative sample

mirrors the population’s characteristics

Mean

the arithmetic average.

Median

the middle score when ordered.

Mode

the most frequent score.

Positive skew

tail to the right (a few very high scores pull the mean up, so mean > median)

Negative skew

tail to the left (a few very low scores pull the mean down, so mean < median).

Range

High minus low

Standard deviation

A measure of variability indicating the typical distance of scores from the mean; larger values mean more spread-out scores.

Histogram

shows frequency of scores across intervals.

Statistically significant

would be unlikely to occur by random chance alone, assuming there is no real effect.

P-value

the probability of observing results at least as extreme as the data, assuming the null hypothesis is true.

Reliability

The consistency of a measure; a reliable test produces similar results under consistent conditions.

Informed consent

participants should understand the study’s purpose, procedures, risks, and their right to refuse or withdraw (within practical limits).

Generazability

The extent to which the results of a research study can be applied to a wider population or different real-world settings outside of the original sample.

Meta-analysis

a statistical method used to combine and analyze the results of multiple independent studies on the same research topic.

Third variable problem

occurs when an unmeasured outside factor drives changes in two correlated variables, creating a false impression that one variable causes the other

Directionality problem

occurs when two variables show a statistical relationship, but researchers cannot tell if Variable A causes Variable B, or if Variable B causes Variable A

Placebo

a fake treatment, like a sugar pill or saline injection, that has no active medical effect

Normal distribution

a data pattern where most values cluster around a central average (the mean), while fewer values spread out symmetrically toward the high and low extremes

Protection from harm

researchers should minimize risk and avoid causing significant physical or psychological harm.

Confidentiality

personal data should be protected; identities should not be revealed without permission.

Debriefing

after participation, researchers explain the study’s true purpose, especially if deception was used, and address questions or distress.

Deception

may be used when it is necessary to prevent demand characteristics (participants changing behavior because they know the hypothesis) and when risks are minimal.

Institutional Review Board (IRB)

which evaluates risks, consent procedures, and protections.

Confederate

an actor or a member of the research team who pretends to be a regular participant

Bimodal Distribution

A frequency distribution of data set that has two district peaks (or modes) where scores tend to cluster.

Informed assent

The explicit, voluntary agreement to participate in a study given by an individual who is not legally competent to provide formal informed consent (such as minors under 18 or cognitively impaired individuals).

Barnum effect

the phenomenon that occurs when individuals believe that personality descriptions apply specifically to them (more so than to other people), despite the fact that the description is actually filled with information that applies to everyone.