AP Psych Unit 0

Research Methods

Independent Variable

the variable whose effect is being studied. It is the variable that gets changed by the researcher.

Dependent Variable

the variable that may change in response to the change of the independent variable.

Operational Definition

a statement of the procedures used to define research variables.

Hypothesis

a testable prediction often implied by a theory.

Falsifiability

the ability of a hypothesis or theory to be proven wrong through observation or experimentation.

Case Studies

a research method in psychology that involves an in-depth examination of a a single individual, group, or phenomenon.

Naturalistic Observations

a research method in psychology where researchers observe and record behavior in real-world settings without intervention or manipulation.

Correlational Research

involves assessing the degree of association between two or more variables that occur naturally using survey, naturalistic observation, and interviews.

Meta-Analysis

a research method in psychology focused on collecting, evaluating, and statistically analyzing data from multiple research studies.

Experiment

a research method in which an investigator manipulates one or more factors to observe the effect on some behaviors and mental processes.

Replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic findings extends to other participants and circumstances.

Generalization

the tendency to respond similarly to stimuli that are similar but not identical to the original conditioned stimulus.

Population

all those in a group being studied from which samples may be drawn.

Representative Sample

a smaller group of participants (or subjects) meant to exactly resemble the population.

Random Sample

a sample in which every person in a population has an equal chance of participating. (allows us to generalize).

Random Assignment

assigning participants to experimental and control groups by chance thus minimizing preexisting differences between two groups.

Control Group

group that does not receive the independent variable.

Experimental Group

group that receives (or reacts to ) the independent variable.

Third Variable Problem

a situation in research where a correlation between two variables may be influenced by an unseen third variable, leading to potentially misleading conclusions about their relationship.

Confounding Variable

a variable that causes differences between the experimental and control groups (other than those caused by the independent variable).

Single Blind Design

a procedure in which participants are unaware of the experimental conditions under which they are operating.

Double Blind Design

a procedure in which both the participants and the experimenters interacting with them are unaware of the particular experimental conditions.

Placebo

a fake treatment assigned to the control group or another group.

Measures of Central Tendency (Mean, Median, Mode)

single scores that represent whole sets of scores.

Variation

how similar or diverse scores are.

Range

the gap between the lowest and highest scores (provides a rough estimate of variation).

Standard Deviation

the computed measure of how much scores vary from the mean score.

Normal Distribution

bell curve that shows how the majority of the data falls near the center, or mean, of the distribution, with progressively fewer values occurring further away from the mean in both directions.

Skewed Distribution

distributions where most of the scores are squeezed into one end (positive = right tail, negative = left tail).

Statistical Significance

determines that the the observed results in a research study are not due to chance.

Correlation Coefficient

a statistical measure of relationship signified by the letter “r” and ranging form -1.00 to +1.00.

Positive Relationship

indicates a direct relationship, meaning that two things increase/decrease together.

Negative Relationship

indicates an inverse relationship, meaning as one things increase, the other decreases.

Scatterplots

graphs on which researchers depict score. Each point plots the value of two variables.