AP Psych Unit 0 Vocab

Quantitative research

Research that collects and analyzes numerical data to describe or explain phenomena.

Dependent variable

The outcome variable measured in an experiment, affected by the independent variable.

Independent variable

The factor manipulated by researchers to observe its effect on the dependent variable.

Confounding variable

An uncontrolled factor that may influence the relationship between variables being studied.

Operational definition

A clear, precise description of how a concept is measured in a study.

Population

The entire group of individuals or items of interest in a study.

Sample

A subset of a population selected for study and analysis.

Representative sample

A sample that accurately reflects the characteristics of the larger population.

Random sample

A sample where each member of the population has an equal chance of selection.

Random selection

The process of choosing participants for a study using chance methods.

Random assignment

Randomly allocating participants to different conditions in an experiment.

Control group

Participants who do not receive the experimental treatment in a study.

Experimental group

Participants who receive the treatment or manipulation in an experiment.

Placebo condition

A fake treatment given to the control group in an experiment.

Placebo effect

Improvement resulting from the belief in a treatment, not the treatment itself.

Single blind study

Participants are unaware of their group assignment in an experiment.

Double blind study

Neither participants nor researchers know group assignments during the experiment.

Correlation

A statistical relationship between two variables, not implying causation.

Causation

A relationship where one variable directly influences or causes changes in another.

Correlational study

Research examining the relationship between variables without manipulating them.

Correlational coefficient (r)

A measure of the strength and direction of a correlation, ranging from -1 to +1.

Illusory correlation

Perceiving a relationship between variables when no real connection exists.

Positive correlation

As one variable increases, the other also tends to increase.

Negative correlation

As one variable increases, the other tends to decrease.

Third Variable problem

An unmeasured variable influences both studied variables, creating a spurious correlation.

Histogram

A graph displaying the frequency distribution of a set of data.

Measures of central tendency

Statistics describing the typical or average value in a dataset.

Normal distribution

A symmetrical, bell-shaped frequency distribution of data around the mean.

Positively skewed data

Distribution with a longer tail on the right side.

Negatively skewed data

Distribution with a longer tail on the left side.

Null hypothesis

The assumption that there is no significant effect or relationship in a study.

Statistical significance

The likelihood that a result is not due to chance alone.

Standard deviation

A measure of variability indicating the average distance from the mean.

Z score

The number of standard deviations a data point is from the mean.

Qualitative research

Research collecting and analyzing non-numerical data to understand concepts and experiences.

Case study

An in-depth investigation of a single individual, group, or event.

Naturalistic observation

Observing behavior in its natural setting without intervention.

Laboratory observation

Observing behavior in a controlled, artificial environment.

Observer effect

Changes in behavior caused by awareness of being observed.

Hawthorne effect

Improved performance resulting from awareness of being studied.

Survey

A method of collecting data by asking people questions.

Wording effects

How the phrasing of questions influences responses in surveys.

Longitudinal studies

Research following the same participants over an extended period.

Cross-sectional studies

Comparing different age groups at a single point in time.

Cross-sequential studies

Combining longitudinal and cross-sectional approaches to study development.

Institutional review board

Committee ensuring ethical treatment of human subjects in research.

Informed consent

Participants' agreement to take part in research after understanding its nature.

Discontinuing participation

A participant's right to withdraw from a study at any time.

Debriefing

Explaining the study's true nature and purpose to participants after completion.

Confidentiality

Protecting participants' identities and personal information in research.

Confederates

Individuals who pose as participants but are actually working with researchers.

meta-analysis

a "study of studies" that combines the findings of multiple studies