Kaarten: Methodology - Chapter 11 - Factorial Designs | Quizlet

factor

An independent variable in an experiment (or a quasi-independent variable in a non-experimental study) especially in those studies that include two or more independent variables.

Factorial design

A research design that includes two or more factors

A single-factor design

A research study with only one independent variable

A two-factor design

A research study involving two or more factors

The quasi-independent variable

The variable that differentiates the groups of participants or the groups of scores in non-experimental and quasi-experimental research.

Main effect

The mean differences among the levels of one factor.

Interaction (between factors)

It occurs whenever two factors, acting together, produce mean differences that are not explained by the main effects of the two factors.

No interaction

When the main effect for either factor applies equally across all levels of the second factor, the two factors are independent.

Interaction

Alternative description, it exists between the factors when the effects of one factor depend on the different levels of a second factor.

Interaction

Alternative description, when the results of a two-factor study are graphed, the existence of non-parallel lines is an indication of it (a statistical test still is needed to determine wether this is statistically significant)

Moderation

Another name for interaction, commonly used in sub-disciplines of the behavioural sciences (e.g.: social psychology, health psychology) used to describe results in non-experimental research designs which do not necessarily follow the factorial design as describe in chapter 11, e.g.: there may not be a discrete number of levels for each quasi-dependent variable.

Interaction

When there is a significant difference in the mean difference for one factor as we move between the levels of the other factor.

Mixed design

A factorial study that combines two different research designs, e.g.: a factorial study with one between-subjects factor and one within-subjects factor.

Combined strategy

When two different research strategies are used in the same factorial design. Where one factor is a true independent variable (experimental strategy) and another factor is a quasi-independent variable (non-experimental or quasi-experimental strategy).

Person-by-environment (PxE) or person-by-situation designs

Designs that add a participant characteristic as a second factor

Higher-order factorial designs

When the basic concepts of a two-factor research design can be extended to more complex designs involving three or more factors. E.g.; a three-factor design

O

Symbol that represents an observation

X

Symbol that represents a treatment

R

Symbol that represents random assignment

No order effects

When the treatment effect does not depend on the order of treatments, the pattern of the data do not show interaction.

Symmetrical order effects

When the second treatment is equally influenced by the first treatment independent of the order of treatments, in the graph of the data the two lines cross exactly at the centre (interaction effect).

Non-symmetrical order effects

When the second treatment is not equally influenced by the first treatment when evaluating the order of treatments, in the graph of the data the two lines do not intersect at their midpoints (interaction effect).

Counterbalancing

Matching to control time-related factors, e.g.: two separate groups of participants with each group going through the set of treatments in a different order.