AP Psych Unit 0

psychology

the scientific study of behavior and mental processes

population

the entire group of individuals or cases that a researcher wants to study and learn about

critical thinking

process of actively evaluating information, research, and human behavior rather than accepting claims at face value

illusory correlations

a cognitive bias where a person perceives a relationship between two unrelated variables, or overestimates how strong that relationship is

hindsight bias

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

overconfidence bias

the tendency to be more confident than correct—specifically, to overestimate the accuracy of our own knowledge, judgments, and physical or mental abilities

falsifiable

able to be disproven by experimental results

hypothesis

a testable prediction, often implied by a theory

operational definition

a precise, measurable description of how a researcher will measure or manipulate a variable in a study

peer review

evaluation of scientific, academic, or professional work by others working in the same field

qualitative data

non-numerical, descriptive information that records qualities, characteristics, opinions, or subjective feelings

quantitative data

numerical information and measurements that can be counted, scored, and analyzed using statistical method

reliability

the extent to which a test or measurement tool yields consistent, stable results

replication

the process of repeating a research study—usually with different participants in different settings or situations—to see whether the original results can be reliably reproduced

self-report bias

a method error that happens when people give inaccurate answers about their own thoughts, feelings, or behaviors on surveys or questionnaires

social desirability bias

the tendency to respond to questions in a socially desirable manner on surveys or questionnaires

theory

an explanation that uses an integrated set of principles to organize observations and predict behaviors or events

validity

the extent to which a test, experiment, or study measures or predicts what it claims to measure

convenience sample

only members of the population who are easily accessible are selected

generalizability

the extent to which the results of a research study can be applied to a larger population or different real-world settings

random assignment

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

random sample

method of selecting from a population in which each person has an equal probability of being selected

representative sample

a sample that accurately reflects the characteristics of the population as a whole

sample

a relatively small proportion of people who are chosen in a study so as to be representative of the whole

sampling bias

a flawed sampling process that produces an unrepresentative sample

case study

a non-experimental research method in which one person is studied in depth in the hope of revealing universal principles

correlational study

a non-experimental research method that measures two or more variables to describe the strength and direction of their relationship without manipulating either variable

experiment

a research method where an investigator manipulates one or more independent variables to observe their effect on a dependent variable while controlling for other factors

meta-analysis

a non-experimental research method method used to combine and analyze the results of multiple independent studies on the same research question

naturalistic observation

a non-experimental research method where psychologists watch and record human or animal behavior in real-world settings without interfering or changing the environment

correlation

a statistical measure that describes the strength and direction of the relationship between two variables (between -1.0 and 1.0)

directionality problem

a limitation in correlational research where a researcher finds a relationship between two variables, but cannot prove which variable causes changes in the other

confounding variable

any factor other than the independent variable that could accidentally influence the dependent variable and ruin an experiment's results

control group

the group of participants in an experiment who do not receive the experimental treatment or manipulation of the independent variable

dependent variable (DV)

the outcome or behavior that a researcher measures in an experiment to see if it changes

double-blind experiment

an experimental procedure in AP Psychology where neither the participants nor the researchers interacting with them know

experimental group

the group of participants in an experiment who are exposed to the treatment or the manipulation of the independent variable

experimenter bias

when a researcher's unconscious expectations, beliefs, or desires about an experiment unintentionally influence the participants' behavior or skew the interpretation of data

independent variable (IV)

the experimental factor that the researcher deliberately manipulates or changes to test its effect on the dependent variable

placebo

an inactive substance or fake treatment (such as a sugar pill or saline injection) that has no actual medical value or therapeutic effect

placebo effect

a phenomenon where a participant's symptoms or behavior improve after receiving an inactive, fake treatment (like a sugar pill or saline injection) simply because they expect or believe it will work

single-blind experiment

an experimental design where the participants do not know whether they are in the experimental group or the control group, but the researchers do know

bimodal distribution

a frequency distribution or data set that has two distinct peaks (or modes), meaning two different values or ranges of scores appear most frequently

effect size

a quantitative measure that describes the strength of a relationship between variables or the magnitude of the difference between groups

negative skew

a data distribution where most scores cluster at the higher end, and a long tail extends toward the lower, negative side

normal distribution

a symmetrical, bell-shaped graph where most data points cluster around the central average (mean), with fewer scores tapering off equally toward the high and low extremes

outlier

an extreme data point or score that lies an abnormal distance away from the rest of the values in a dataset

percentile rank

the percentage of scores in a distribution that fall at or below a particular score

positive skew

an asymmetrical distribution where most scores cluster at the lower end (left side) and a long tail extends toward the higher end (right side) due to a few extreme high scores

standard deviation

a measure of variability that calculates the average distance or how far scores in a data set fall from the mean

statistical significance

a mathematical statement indicating that the results of a study or experiment are reliable and unlikely to have occurred by random chance alone

mean

the arithmetic average of a dataset, calculated by adding all the scores together and dividing by the total number of scores

median

the middle score in a distribution or data set when all the values are arranged in numerical order

mode

a measure of central tendency that represents the most frequently occurring score or value in a data set

range

the numerical difference between the highest and lowest scores in a data set.

confederates

an actor or research assistant who secretly works for the experimenter while pretending to be a regular participant.

confidentiality

an ethical guideline requiring researchers and therapists to keep participants' or clients' personal data and private information secure and hidden from the public.

debriefing

is the ethical requirement where researchers explain the true purpose, procedures, and any deception used in a study to participants after the experiment ends.

deception

the practice of intentionally misleading or withholding information from research participants about the true purpose or procedures of a study.

informed assent

the agreement given by a minor or someone who lacks legal capacity to participate in a study, after the research is explained using age-appropriate or simple language.

informed consent

the ethical rule that research participants must know the purpose, risks, and procedures of a study so they can freely choose whether to join.

Institutional Review Board (IRB)

an administrative committee at a research institution or university that reviews research proposals involving human participants before any study begins to ensure ethical guidelines are met.

protection from harm

an ethical guideline requiring researchers and clinicians to ensure that participants and clients are safeguarded from unnecessary physical, emotional, or psychological pain, stress, or distress during a study or treatment.

behavioral

a school of thought that explains all human and animal actions as learned behaviors shaped by the environment, focusing strictly on observable actions rather than internal mental processes.

biological

a viewpoint that explains human behavior and mental processes through physical and physiological causes, such as genetics, the nervous system, brain structures, and hormones

cognitive

an approach that explains human behavior and mental processes by focusing on internal thoughts, perception, memory, and information processing.

evolutionary

a viewpoint that explains human behaviors and mental processes as adaptive traits shaped by natural selection to help our ancestors survive and reproduce.

humanistic

an approach that emphasizes personal growth, free will, and the innate drive of individuals to achieve their full potential.

psychodynamic

a psychological approach that emphasizes how internal conflicts, unconscious drives, and early childhood experiences shape human behavior and personality.

sociocultural

an approach that explains human thinking, feeling, and behavior as a result of cultural norms, social expectations, and group contexts rather than internal biology alone.