AP Psychology - Research Methods

Naturalistic Observation

A descriptive research method involving observing animal or human behavior in natural settings rather than the laboratory.

Case Study

An in-depth investigation of an individual subject(s).

Survey

Descriptive research technique in which researchers use questionnaires or interviews to gather information about specific aspects of participants’ behavior.

Experiment

allows researchers to determine cause and effect relationships

Hypothesis

a belief about the relationship between variables

Operational Definition

Describes the actions or operations that will be used to measure or control a variable

Independent Variable

selected by the researcher and is what is thought to be the cause

Dependent Variable

selected by the researcher and is what the research hopes will happen

Confounding Variable

occurs when two variables are linked together in a way that makes it difficult to sort out their special effect. (aka extraneous variable)

Experimental Design

the group in an experiment that receives the variable being tested

Control Group

Subjects who do not receive the special treatment given to the experimental group.

Population

the larger collection from which the sample is drawn

Sample

collection of subjects selected in an empirical study

Random Sample

a part of the sampling technique in which each sample has an equal probability of being chosen

Random Assignment

Assigning participants to experimental groups and control groups by chance

Single-Blind Procedure

research strategy in which the subjects are unaware of which group they are in

Double-Blind Procedure

A researcher strategy in which neither subjects nor experimenters know which subjects are in the experimental or control groups

Correlation

Exists when two variables are related to each other

Correlation Coefficient

A numerical index of the degree of the relationship between two variables. Stronger to negative 1 or positive means a high correlation

Scatterplot

a chart that shows the relationship between two variables

Illusory Correlation

The perception of a relationship when none exists

Mean

Average score, Extreme scores have a greater impact on the mean than on the mode or median

Median

Score that divides a frequency distribution exactly in half, so that the same number of scores lie on each side (middle)

Mode

Most frequently occurring score

Range

highest minus the lowest.

Standard Devation

a standard measurement of how much the scores in a distribution deviate from the mean

Statistical Significance (p-value)

the distance of a score from the mean in units of standard deviation