Experimental Basics
This type of research is the only method capable of establishing causal relationships.
What is experimental research?
A variable that unintentionally varies along with the independent variable.
What is a confound?
A factorial design has more than one of these.
What are independent variables?
The effect of one independent variable averaged across levels of another.
What is a main effect?
The average score in a distribution.
What is a mean?
Darley & Latané manipulated this variable in their bystander effect study.
What is the number of witnesses?
Assigning participants to conditions in a way that equalizes groups.
What is random assignment?
A “2 × 3” design has this many total conditions.
What is 6 conditions?
When the effect of one independent variable depends on the level of another.
What is an interaction?
The middle score when data are ordered.
What is the median?
Holding all variables constant except the independent variable.
What is experimental control?
Whether the manipulation truly represents the intended construct.
What is construct validity?
Each combination of levels across all independent variables.
What is a condition (or cell)?
In Schnall’s disgust study, harsh moral judgments increased only for participants high in this trait.
What is private body consciousness?
A graph showing the relationship between two quantitative variables.
What is a scatterplot?
The variable measured to assess the effect of the manipulation.
What is the dependent variable?
When the relationship between two variables is actually caused by a third variable.
What is the third-variable problem?
Clean vs. messy rooms in Schnall’s disgust study represent this type of manipulation.
What is an environmental manipulation?
A factorial design that includes both manipulated and measured variables.
What is a mixed factorial design?
A measure of how spread out scores are around the mean.
What is the standard deviation?
When participants behave differently because they know they’re being studied.
what are demand characteristics (reactivity)?
The degree to which results can be generalized beyond the study.
What is external validity?
A variable that is measured rather than manipulated in a factorial design.
What is a subject variable?
Non‑parallel lines on a plot indicate this.
What is an interaction?
A statistic describing the strength and direction of a relationship between variables.
What is a correlation coefficient?