Unit 0: Science Practices

AP Psychology

Confirmation Bias

Tendency to focus on information that confirms existing beliefs

Hindsight Bias

Tendency to believe, after an event occurs, that the outcome was predictable

Overconfidence

Tendency to overestimate the accuracy of one’s knowledge or judgements

Independent vs. Dependent Variable

Independent: Variable manipulated by the researcher to observe its effect

Dependent: Variable that is being measured

Random Assignment

Assigning participants to groups by chance to reduce preexisting differences

Case Study

An in-depth examination of an individual or small group

Correlation

A statistical measure indicating the strength and direction of the relationship between two variables

Meta-Analysis

A quantitative method that combines results from multiple studies to identify trends

Naturalistic Observation

Observing and recording behavior in its natural environment without intervention

Hypothesis

Testable prediction about a relationship between variables

Falsifiable Hypothesis

Hypothesis that can be proven false through evidence

Operational Definitions

Precise description of how a variable is measured or manipulated

Confounding Variables / Third Variable Problem

An extraneous factor that may influence the dependent variable

Histogram

A graph representing the frequency distribution of data

Scatterplot

A graph showing the relationship between two variables; correlation is indicated by the pattern

Central Tendency

A statistic that represents the center or typical value of a dataset

Variation

A measure of the spread or dispersion of data

Percentile Rank

The percentage of scores in a distribution that fall below a given score

Range

The difference between the highest and lowest scores in a dataset

Standard Normal Curve

A bell-shaped curve representing a normal distribution of scores

Mean

The arithmetic average of a set of scores

Median

The middle score in an ordered dataset

Mode

The most frequently occurring score in a dataset

Population

The complete set of individuals or items that a researcher is interested in studying

Representative Sample

A sample that accurately reflects the characteristics of the population

Random Sample

A sample in which each member of the population has an equal chance of being selected

Convenience Sampling

A sample composed of participants who are easily accessible

Sampling Bias

Systematic errors that occur when a sample does not represent the population

Generalization

The process of applying results from a sample to the larger population

Experimental Group

The group that receives the treatment or manipulation

Control Group

The group that does not receive the treatment; used as a baseline for comparison

Placebo

An inactive treatment given to control participants to control for expectations

Single-Blind Study

A study in which participants do not know which group they are in

Double-Blind Study

A study in which neither participants nor researchers know group assignments

Experimenter Bias

When a researcher’s expectations influence the outcome of a study

Social Desirability Bias

The tendency of participants to respond in ways they believe are socially acceptable

Self-Report Bias

Bias introduced when participants’ responses are affected by memory errors or personal attitudes

Qualitative Data

Non-numerical data collected through observations, interviews, or text analysis

Quantitative Data

Numerical data collected through measurements or surveys

Peer Review

Evaluation of research by experts before publication to ensure accuracy and credibility

Replication

Repeating a study to verify the reliability of its findings

Statistical Significance

The probability that results are not due to chance, typically p < 0.05

Correlation ≠ Causation

The observation that a relationship between variables does not prove one causes the other

Institutional Review Board (IRB)

Committee responsible for ensuring that research meets ethical standards

Animal Research Ethical Standards

Guidelines requiring humane treatment and minimizing harm to animals

Human Ethical Research Standards: Informed Consent

Participants are fully informed about the study and voluntarily agree to participate

Human Ethical Research Standards: Protection from Harm

Participants are safeguarded from physical or psychological risk

Human Ethical Research Standards: Confidentiality

Participants’ data are kept private

Human Ethical Research Standards: Deception/Use of Confederates

Only allowed when necessary and ethically justified

Human Ethical Research Standards: Debriefing

Participants are fully informed about the study’s purpose and procedures after participation