Exam 12: Analysis of Variance

On a factorial ANOVA, the number of different variations in treatment conditions, determines the number of

The one-way ANOVA may only be used when

Calculate the F ratio on the following sets of scores. Group 1 Group 2 Group 3 5 8 10 4 6 10 1 6 12 1 5 8

Questions below are based on the following: (This is similar to an item in the text at the back of chapter 12 but WITH A DIFFERENT DATA SET). A researcher is interested in whether a certain amphetamine drug will affect the retention of learned behavior among rats as a function of how much time is allowed to elapse between the training and the retention test. Four groups, ten subjects in each group, were randomly selected from a colony of Sprague-Dawley rats. All the rats were given the same amount of training on a simple maze. Groups A and C were given the amphetamine, whereas Groups B and D were given a placebo. Groups A and B were tested for retention immediately following the training, whereas Groups C and D were tested 4 hours later. The retention measure consisted of a scaled score based on how many correct responses the rats would exhibit while running the maze, the higher the score the higher the retention FACTOR A Amphetamine Group A Placebo Group B 15 13 9 9 9 12 Immediate 11 7 Test 10 7 6 8 10 10 12 9 14 5 7 11 FACTOR B Group C Group D 1 8 5 6 Delayed 2 9 Test 4 4 5 4 6 5 5 6 2 6 6 6 1 7 -What conclusions might you draw?

When doing a factorial ANOVA, the main effects are found from the

When the distribution of scores within a sample forms a platykurtic shape, then

An ANOVA cannot be done unless the sample sizes are unequal.

For questions below use the data on the following page: A researcher is interested in establishing whether memory is a function of both IQ and time of testing. A random sample of 40 university students was selected and each student was given an IQ test. Half of the students scored above 115 and were assigned to the high IQ category. The students were than all given a series of paragraphs to read, followed by a memory test on the content of what had been read. Half the students took the memory test immediately after reading the material, while the other half waited an hour before testing. The results were as follows (high scores indicating better memory retention): -Find the F ratio for columns, and if significant, state the alpha level.

When several independent variables are manipulated simultaneously, an appropriate analysis would be the

An F ratio of 5, tells us specifically that the variance between groups is

For questions below use the data on the following page: A researcher is interested in establishing whether memory is a function of both IQ and time of testing. A random sample of 40 university students was selected and each student was given an IQ test. Half of the students scored above 115 and were assigned to the high IQ category. The students were than all given a series of paragraphs to read, followed by a memory test on the content of what had been read. Half the students took the memory test immediately after reading the material, while the other half waited an hour before testing. The results were as follows (high scores indicating better memory retention): -Was the column independent variable manipulated or assigned?

The factorial ANOVA should not be used unless there is more than one independent variable.

If one had to calculate 15 successive t tests, it would mean

If the F ratio were performed on a two-group design and F were equal to 9, then t would be equal to

Calculate the F ratio on the following sets of scores. Group 1 Group 2 Group 3 4 6 7 3 3 5 1 2 1

When analyzing experimental research via the F ratio, the action of the independent variable is most clearly shown in the value of the

The F ratio may only be calculated when the independent variable has exactly two levels.

The concept of "between variability" is based on

On a factorial ANOVA, a significant interaction indicates

For questions below use the data on the following page: A researcher is interested in establishing whether memory is a function of both IQ and time of testing. A random sample of 40 university students was selected and each student was given an IQ test. Half of the students scored above 115 and were assigned to the high IQ category. The students were than all given a series of paragraphs to read, followed by a memory test on the content of what had been read. Half the students took the memory test immediately after reading the material, while the other half waited an hour before testing. The results were as follows (high scores indicating better memory retention): -Find the F ratio for rows, and if significant, state the alpha level.