PSYC012 Multiple Independent Variables

What is a factorial design?

An experiment with two or more independent variables.

What are independent variables in the context of factorial design?

Factors that are manipulated to observe their effect on the dependent variable.

What is a dependent variable?

The outcome that is measured in an experiment to see the effect of the independent variables.

What is the notation for a 2x2 factorial design?

It indicates 2 factors, each with 2 levels.

What does the product of the numbers in factorial notation indicate?

The total number of cells in the design.

What is a main effect?

The overall effect of one independent variable on the dependent variable, ignoring other variables.

What is a marginal mean?

The mean for one level of one independent variable, averaged across levels of the other independent variable.

What is an interaction effect?

A test of whether the effect of one independent variable depends on the level of another independent variable.

What is a simple effect?

A comparison between two cells in a factorial design.

What is a crossover interaction?

An interaction where the effect of one independent variable reverses across levels of another independent variable.

What is a spreading interaction?

An interaction where the effect of one independent variable is stronger at one level of another independent variable.

What is factorial ANOVA?

A statistical test that provides an F statistic and p-value for each main effect and interaction term.

What is contrast testing?

A series of t-tests that individually test different patterns of means across cells.

What is an independent-groups factorial design?

A design where both independent variables are manipulated between subjects.

What is a repeated-measures factorial design?

A design where both independent variables are manipulated within subjects.

What is a mixed factorial design?

A design where one independent variable is between subjects and one is within subjects.

In Example #1, is there a main effect of valence?

No, the marginal means for negative and positive experiences are the same.

In Example #2, what was the main effect of valence?

Yes, participants reflecting on negative experiences reported lower well-being than those reflecting on positive experiences.

In Example #3, what was the main effect of mode of processing?

Yes, there was a main effect indicating differences in well-being based on the mode of processing.

What is the difference between writing and thinking in terms of mode of processing?

These are two levels of the independent variable 'mode of processing' in the factorial design.

What does 'cell' refer to in a factorial design?

A particular combination of the conditions of each independent variable.

What does it mean if an interaction effect is significant?

It indicates that the effect of one independent variable changes at different levels of the other independent variable.

How many interaction effects are possible in an experiment with two independent variables?

One possible interaction effect.

What is the purpose of testing interaction effects?

To understand how independent variables work together to influence the dependent variable.

What is a dependent variable in the context of the examples provided?

Well-being, as measured by participants' reflections on experiences.

What is the main effect of mode of processing?

Participants who wrote about their experience reported higher well-being than those who thought about the experience.

Is there an interaction effect between experience valence and mode of processing?

No, there is no interaction effect.

What was found regarding the main effect of valence?

There is no main effect of valence.

In Example #4, what was the well-being score for writing about a positive experience?

6

In Example #5, what was the well-being score for thinking about a negative experience?

2

What does a main effect indicate in this context?

A main effect indicates that one independent variable significantly affects the dependent variable.

What was the well-being score for writing about a negative experience in Example #6?

4

What is a crossover interaction effect?

A crossover interaction effect occurs when the effect of one independent variable depends on the level of another independent variable.

In Example #6, what was the main finding regarding interaction effects?

Writing was more beneficial than thinking about negative experiences, but thinking was more beneficial than writing about positive experiences.

What is the significance of finding an interaction effect?

If an interaction effect is found, the main effects can be misleading and are less interesting.

What was the score for thinking about a positive experience in Example #4?

4

What does a main effect of valence indicate?

It indicates that participants reflecting on negative experiences reported lower well-being than those reflecting on positive experiences.

What is the score for writing about a negative experience in Example #5?

6

What is the structure of a 2 x 3 factorial design?

It has 2 levels of one independent variable and 3 levels of another, resulting in 6 cells.

What is a three-way interaction effect?

A three-way interaction effect occurs when the interaction between two independent variables depends on the level of a third independent variable.

In Example #4, what were the scores for writing and thinking about negative experiences?

Writing: 4, Thinking: 2

What were the scores for writing and thinking about positive experiences in Example #6?

Writing: 2, Thinking: 4

What is the implication of a significant main effect in psychological studies?

It suggests that the independent variable has a direct impact on the dependent variable.

What is the score for writing about a positive experience in Example #5?

6

What does it mean if marginal means are different?

It suggests that there may be a significant main effect for that variable.

What is the score for thinking about a negative experience in Example #6?

2

What is the significance of having more than 2 levels of independent variables?

It increases the complexity of the design and the potential for discovering interactions.

What were the scores for writing and thinking about experiences in Example #5?

Writing: 6, Thinking: 2

What is the role of experience valence in the study?

Experience valence refers to the positive or negative nature of the experiences reflected upon by participants.

How does writing about experiences affect well-being compared to thinking?

Writing generally leads to higher reported well-being than thinking, especially for negative experiences.

What does the term 'marginal means' refer to?

Marginal means refer to the average scores for each level of an independent variable, regardless of other variables.

What is the main finding regarding the interaction effect in Example #5?

There is a spreading interaction effect, indicating different impacts based on the type of experience and mode of processing.