PSY230 Final (Conceptual)

In an ANOVA, the variance explained by the model is assumed to include

Correct: the effect of the IV, as well as individual differences, etc.

You conduct a factorial ANOVA and see the following graph. The ANOVA you conducted can be described as a:

2 x 2 ANOVA

This diagram represents the partitioning of variance in a two-way ANOVA. Match the letter with what it represents. A ( B ) - (C) (D)- (E) - (F)

A: B. Total variance B: A. Variance explained by model C: F. Variance explained by error D: D. Variance explained by variable 1 E: C. Variance explained by variable 2 F: E. Variance explained by interaction between variable 1 and variable 2

This diagram represents the partitioning of variance in a one-way ANOVA. Match the letter with what it represents. A B<>C

A: MStotal B: MSmodel C: MSerror

Match the following: 1. Total variability (SStotal) 2. Variability explained by the model (SSmodel, also called SSbetween) 3. Variability not explained by the model (SSerror, also called SSwithin)

Answers: 1= A. The sum of the squared differences between each data point and the overall mean 2= C. The sum of the squared differences between the mean of the group and the overall mean, once for each data point. 3= B. The sum of the squared differences between each data point and the mean of the group it is in

Based on the graph above, which one of the following answers is correct?

Correct: There is a main effect for Time of Exercise . Answers: There is a main effect for Intensity of Exercise. There is an interaction between the two factors. There is a main effect for Time of Exercise. There appears to be no main effects and no interaction.

Which of the following is true regarding the advantages of conducting a factorial ANOVA over conducting two, separate one-way ANOVAs?

Correct: A factorial ANOVA allows evaluation of both the main effects of the two independent variables and the interaction between them. Answers: A factorial ANOVA allows evaluation of both the main effects of the two independent variables and the interaction between them. The factorial ANOVA is less complicated than the one-way ANOVA. In a factorial ANOVA, the dependent variable can be measured on any of the four scales of measurement. There are no advantages of conducting a factorial ANOVA rather than two separate one-way ANOVAs.

I want to see if the effects of coffee on cognitive performance are better when my students drink a lot of coffee than if they drink a little coffee. I also want to see if this effect is bigger for expensive coffee than for cheap coffee. I break my subjects into four groups, who drink: 3 cups of expensive coffee from Starbucks 1 cup of expensive coffee from Starbucks 3 cups of cheap coffee from McDonalds 1 cup of cheap coffee from McDonalds Then I give them a test of cognitive performance. If I find that overall students do better when they drink a lot of coffee than if they drink a little coffee, averaging across both cheap and expensive coffee that would be:

Correct: A main effect of coffee amount Answers: A main effect of coffee price A main effect of coffee amount An interaction between coffee price and coffee amount A lack of interaction between coffee price and coffee amount

I want to see if the effects of coffee on cognitive performance are better when my students drink a lot of coffee than if they drink a little coffee. I also want to see if this effect is bigger for expensive coffee than for cheap coffee. I break my subjects into four groups, who drink: 3 cups of expensive coffee from Starbucks 1 cup of expensive coffee from Starbucks 3 cups of cheap coffee from McDonalds 1 cup of cheap coffee from McDonalds Then I give them a test of cognitive performance. If I find that the amount of coffee students drink has a bigger effect on cognitive performance for expensive coffee than it does for cheap coffee does, that is

Correct: An interaction between coffee price and coffee amount Answers: A main effect of coffee price A main effect of coffee amount An interaction between coffee price and coffee amount A lack of interaction between coffee price and coffee amount

A significant F test (i.e., F obt ≥ F crit ) provides sufficient information to identify which group(s) differed from the others.

Correct: False True False

Why don't we use multiple t tests instead of an ANOVA to compare group means?

Correct: Multiple t tests would increase (inflate) the probability of a Type I error. Answers: Correct Multiple t tests would increase (inflate) the probability of a Type I error. There is no reason. Each researcher should decide which approach to use. The ANOVA accomplishes everything the t tests could do in a single formula. There are fewer assumptions with the ANOVA. For example, the ANOVA does not require homogeneity of variances

___________ is a relatively unbiased estimate of an ANOVA's effect size.

Correct: Omega squared Answers: Eta squared r2 Omega squared Cohen's d

Which of the following is true?

Correct: Reject H0 when Fobt ≥ Fcrit. Reject H0 when Fobt ≤ Fcrit. Reject H0 when p > α. Reject H0 when Fobt ≤ dfbetween.

I want to see if the effects of coffee on cognitive performance are better when my students drink a lot of coffee than if they drink a little coffee. I also want to see if this effect is bigger for expensive coffee than for cheap coffee. I break my subjects into four groups, who drink: 3 cups of expensive coffee from Starbucks 1 cup of expensive coffee from Starbucks 3 cups of cheap coffee from McDonalds 1 cup of cheap coffee from McDonalds Then I give them a test of cognitive performance. What sort of statistical test should I use to test this?

Correct: Two-way ANOVA Answers: Paired-samples t-test Independent-samples t-test One-way ANOVA Two-way ANOVA

You are designing an experiment that will use of a one-way ANOVA. Your independent variable is Time of Day and includes the following three categories: morning, afternoon, and evening . In statistical terminology, Time of Day is known as a ________________.

Correct: factor confound factor level ancillary variable

A _________________ experiment is one in which the effects of two or more factors are assessed in one experiment.

Correct: factorial Factorial two-tailed parametric inferential

In a one-way ANOVA, if there is an effect of my independent variable, I would expect the F-ratio to be:

Correct: greater than 1 Answers: less than 1 equal to 1 greater than 1 no way to know from information given

A/an __________ effect is the effect of one factor averaged across the levels of the other factor.

Correct: interaction Answers: residual interaction anomalous main

In an ANOVA, the variance not explained by the model (the error variance) is assumed to include

Correct: only individual differences, etc. Answers: the effect of the IV, as well as individual differences, etc. only individual differences, etc. only the effect of the IV.

The model that I am using when I perform an ANOVA is that:

Each individual is predicted to have a score equal to the group mean.

Based on the graph above, is the following statement true or false? There appears to be an interaction occurring in this factorial ANOVA.

False

F obt = _______________________________.

MS model/ MS error

The effect size estimates eta squared and omega squared represent:

The percentage of total variability in the dependent variable that is accounted for by the independent variable.

A/an __________ effect is the effect of one factor averaged across the levels of the other factor.

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