AP Psych Unit 1, Lecture 4: Research Methods

Vocabulary and key concepts from AP Psychology Unit 1 Lecture 4 covering various research methodologies, experimental design, and the distinction between correlation and causation.

Correlational Studies

A type of research that checks the degree of association between two or more variables that occur naturally.

Scatterplot

A graphical representation of the relationship between two measures obtained on a group of individuals.

Survey Research

A research method that consists of giving a large, representative sample of people a set of questions to answer.

Naturalistic Observation

A type of study in which the researcher watches and takes notes on the activities of subjects in their normal environment to see them acting authentically.

Case Studies

Intensive psychological studies of a single, often atypical, individual used to understand rare behaviors or psychological states.

Genie

A specific case study subject found in $1970$ at age $14$ who was studied to see if she could develop language after spending her first $14$ years in extreme isolation.

Longitudinal Studies

Studies in which researchers conduct several observations of the same group of people over a period of time.

Perry Preschool Study

A longitudinal study started in $1962$ that followed $123$ low-income Black children through age $40$ to assess the effects of pre-K.

Cross-Sectional Studies

Studies that compare different population groups, such as different ages, genders, or incomes, at one moment in time.

Experiment

An investigation in which a hypothesis is scientifically tested using independent and dependent variables.

Hypothesis

A testable prediction often formatted as an "If ____, then ____" statement.

Independent Variable

The treatment or factor that the researcher manipulates; it is what the researcher does.

Dependent Variable

The result or outcome in an experiment; it is the factor that the researcher measures.

Control Group

The group of subjects in an experiment who do not receive the treatment.

Treatment Group

The group of subjects in an experiment who receive the actual treatment being tested.

Placebo

A fake treatment, such as a fake pill, given to the control group during an experiment.

Random Selection

The process of getting the most random possible group out of a target population for a study.

Random Assignment

The procedure of randomly dividing study participants into the control group or the treatment group.

Correlation Coefficient ($r$)

A statistical measure of the strength of a relationship, such as the $0.958648$ correlation between mozzarella cheese consumption and civil engineering doctorates.