Exam 13: Analysis of Variance: Factorial Design

In a 3 x 4 factorial design with five participants per cell, the df for the interaction F would be

Data Set 13-6: The numbers in the cells are means based on samples of 5 in each cell. Experiment X 5 10 10 5 Experiment 5 10 5 10 \ Experiment 5 5 5 10 -In Data Set 13-6, the main effect of B could be significant in

Suppose you had a 2 x 2 table with the four cell means and you knew that N was 6 for each cell. With this information you could not calculate

Data Set 13-10: The bar graphs show the results of Experiment X and Experiment Y. Each bar is based on a sample of 8. -In Data Set 13-10, the main effect for B appears to be significant in Experiment

Data Set 13-7: A political scientist reported a study on attitudes toward increasing military expenditures. The attitudes of four groups were reported: US Army officers, corporate managers, public school teachers, and assembly-line workers. Within each of the categories, those under age 35 were tabulated separately from those over 35. A factorial ANOVA on the data produced a significant interaction; the main effect for age was not significant. -The degrees of freedom for the interaction mean square in Data Set 13-7 is

A histogram with stairs steps that ascend for one treatment and descent for the other treatment indicates a significant interaction.

The sum of squares for cells is equal to the sum of the sums of squares of A, B, and error.

A 4 x 4 factorial ANOVA with 12 scores per cell produced a MS_AB = 44 and a MS_error = 24. For either factor with 4 levels and $\alpha$ = .05, a Tukey HSD would

If the interaction is significant, a Tukey HSD is not appropriate.

In the Cub Scouts, the Pinewood Derby is a big event. Little boys, with a bit of help from their daddys, carve a 6-inch race car and attach wheels. Several cars race down an incline and a winner is declared. Sometimes the winner even gets his picture in the paper. Daddys often know of ways to increase the speed of the car. Smoothing the axle with emery cloth (a kind of sandpaper for metal) will reduce the race time one second. Putting graphite (a lubricant) on the axle will reduce the race time three seconds. Suppose some ingenious daddy did both to his son's car. Which change in that car's race time is not indicative of an interaction between emery cloth and graphite?

Among behavioral scientists, factorial ANOVA designs were used in __________ of a sample of articles.

Faced with the need to establish a second high school, the school board in a small city hired psychology students at the local college to conduct a poll to assess the attitudes of students, parents, and teachers toward the proposed change. The students added the variable of gender to their questionnaire. Analyze the data and write a conclusion. High scores mean favorable attitudes. Students Parents Teachers 20 16 10 18 14 9 Males 16 10 7 14 9 7 12 7 5 Students Parents Teachers Females 25 21 14 23 20 13 19 20 11 19 18 10 15 14 9

Which of the following expresses a significant interaction?

The effect size index. f, can be used on factorial ANOVA problems.

Data Set 13-6: The numbers in the cells are means based on samples of 5 in each cell. Experiment X 5 10 10 5 Experiment 5 10 5 10 \ Experiment 5 5 5 10 -In Data Set 13-6, the main effect of A is not significant in

Data Set 13-1: An F value of 2.75 was obtained when an interaction mean square was divided by a error mean square. The degrees of freedom were 6 and 18. -Refer to Data Set 13-1. The number of factors in this design must have been

An experimenter was interested in the effect of expectations and drugs on time perception. She gave participants either an amphetamine (a stimulant) or a placebo (an inert substance) and told them that they had received a stimulant or told them that they had received a depressant. The design looks like this: Actually Received Told They Received Stimulant Depressant Stimulant =205 =89 \Sigma=6000 =1150 Placebo =195 =37 \Sigma=5500 =283 N=8 per cell The score each participant received was a composite of several time-perception measures. Higher scores mean that time perceived as passing more quickly than it is. Perform an ANOVA with $\alpha$ = .05 and interpret the results. Include a summary table.

A 3 x 5 factorial ANOVA has two independent variables.

A social psychologist was interested in the effect of propaganda on attitudes of males and females. He measured attitudes toward democracy for all participants, delivered the propaganda, and remeasured attitudes toward democracy. He wanted to analyze the data using a 2 x 2 factorial with gender as one independent variable and before-and-after attitudes as the other. The techniques presented in the text will not permit this because

With respect to the number of independent variables, which of these designs is not like the others?