AP PSYCH AP EXAM TERMS

Experiments

A research method where a researcher manipulates a variable to test cause-and-effect relationships.

Correlational Studies

 Studies that measure the relationship between two variables without proving cause and effect.

Survey

A method of collecting self-reported data using questionnaires or interviews.

Naturalistic Observation

Observing behavior in its natural environment without interference.

Case Study

An in-depth study of one person or a small group.

Qualitative Research

Research using non-numerical data (descriptions, interviews)

Quantitative Research

Research using numerical data and statistics.

Cross sectional Studies

Compare different age groups at one point in time.

Cross Sequential Studies

Combines cross-sectional and longitudinal methods.

Quasi Experiments

Studies without random assignment; no true cause-and-effect conclusions.

Empirical Investigation

Research based on observation and measurable evidence.

Scientific Method

question → hypothesis → experiment → analyze → conclude

Theory

A well-tested explanation of behavior or mental processes.

Hypothesis

A testable prediction.

Operational Definition

A clear, measurable definition of variables.

Falsifiable

Able to be proven wrong. (forces rejection of progressing scientific ideas)

Meta-Analysis

Combines results from multiple studies.

Peer Reviewers

Experts who evaluate research before publication.

Dependent Variable

The variable measured (The outcome/results)

Confounding Variable

A factor that could affect results if not controlled.

Experimenter Bias

Researcher expectations influence results.

Random Sampling

Selecting participants randomly from a population.

Random Assignment

Assigning participants randomly to groups.

Control Group

no treatment group

Experimental Group

Receives treatment group

Sampling Bias

Sample does not represent the population.

Placebo Effect

Improvement due to belief in treatment.

Representative Sample

Accurately reflects the population.

Confirmation Bias

Tendency to search for info that supports beliefs.

Double Blind Study

Neither participants nor researchers know who gets treatment.

Single Blind Study

Only researcher knows who receive treatment, not the participants.

Replication

Repeating a study to confirm results.

Hindsight Bias

 Believing you “knew it all along.”

Social Desirability Bias

Answering to look good socially.

Self-Report Bias

A type of bias where participants give inaccurate answers about themselves, often because they forget, misunderstand, or want to look good

Mean

Average

Median

middle value

mode

most frequent value

Range

Highest minus lowest score

Standard Deviation

Average distance from the mean.

Correlation Coefficient

Number from -1 to +1 showing strength/direction of relationship.

Debriefing

Explaining the study after participation.

Deception

Misleading participants (only if justified).

Informed Consent

Participants must be informed and agree.

Confidentiality

Participants data kept private

Anonymity

Identity is unknown.

Assent

Agreement from minors to participate.

APA

Sets ethical guidelines

Right to Withdraw

Participants can leave anytime.

Correlation

Relationship between variables.

Normal Curve

Bell-shaped distribution

Likert Scale

A rating scale used in surveys where people indicate how much they agree or disagree with a statement

Frequency Distribution

Graph showing how often values occur.

Regression Toward the Mean

Extreme scores move closer to average over time.

Scatterplot

Graph showing relationship between two variables.

Illusory Correlation

Seeing a relationship that isn’t real.

Statistical Significance

Results unlikely due to chance.

Minimize Risk and Discomfort

Protect participants from harm.

Percentile rank

Percentage of scores below a given score.

Positive Skew

Tail on right

Negative skew

tail on left

IRB

Committees that approve research.

Effect Size

Strength of a relationship or difference.

Descriptive Statistics

Methods used to organize and summarize data (Ex: mean, median)

Inferential Statistics

Methods used to draw conclusions or make predictions about a population based on a sample. (Ex: taking a survey and making assumptions on the results.)

Frequency Distribution

A graph or chart that shows how often each value appears in a set of data.

Evolutionary Psychology

 Studies how behavior is shaped by evolution.

Natural Selection

Traits that help survival are passed down more often.

Genome

Complete set of genetic material.

Phenotype

observable traits

Genotype

genetic makeup

DNA

Molecule that carries genetic information.

Mutation

Random change in DNA.

Nature

Behavior is influenced by genetics

Nurture

Behavior is influenced by experiences/environment

Autopsy

Examining the brain after death.

Lesioning

Destroying brain tissue to study function.

Nerves

Bundles of neurons.

Central Nervous System

Brain and spinal cord.

Peripheral Nervous System

Nerves, and components outside the CNS

Split-Brain Research

Studies people with separated hemispheres.

MRI

Detailed images of brain structure.

Charles Darwin

Scientist who proposed evolution through natural selection.

Epigenetics

The study of how environment and experiences affect gene expression without changing the DNA sequence.

Heredity

passing traits to offspring

Heritability

how much genes explain differences in a group of people.

EEG

Records brain’s electrical activity.

CT Scan

X-ray images of brain structure.

PET Scan

Shows brain activity using glucose.

Case Studies

In-depth study of one person/small group

fMRI

Shows brain activity and structure.

MEG

Measures magnetic fields from brain activity.

Spinal Cord

Sends messages between brain and body.

Sympathetic nervous system

Arouses body (fight-or-flight).

Parasympathetic nervous system

Calms body (rest-and-digest).

Autonomic Nervous System

 Controls involuntary actions.

Somatic Nervous System

Controls voluntary movement.

Michael Gazzaniga

Led major split-brain research.

Pituitary Gland

“Master gland” controlling others.

Pineal Gland

Gland that controls sleep (melatonin).