Exam 12: Analysis of Variance

An F ratio which equals exactly 1.00, indicates that

The larger the F ratio

The F ratio was developed by

For the F ratio, if alpha is set at .05, it remains at .05 if comparisons are made between (among)

When doing an F ratio, subtracting the constant, 1, from the total number of sample groups yields the

If the tabled value for F, for a given number of degrees of freedom, were equal to 5.14, and the calculated value of F also was equal to 5.14, then

In order to calculate an F ratio, there must be

When four leptokurtic sampling distributions show no overlap whatever, then

When the variance within a sample group is equal to 16, then the standard deviation for that sample is equal to

Three groups of subjects were randomly selected, four subjects in each group. The SS between was 132.17, and the SS within was 19.50. a. Calculate the F ratio b. Should Ho be rejected ? If rejected, state the probability of a Type 1 error.

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 MS for interaction.

With the F ratio, the overall hypothesis among 4 group means may be tested by making

With the t test, as the number of decisions to reject Ho increases, so too

When the calculated F ratio is equal to or greater than the critical, tabled value of F for a given number of degrees of freedom, then

When doing an F ratio on a four-group design, 4 subjects in each group, the between degrees of freedom will equal

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 -Is the row F ratio significant?

When the within sum of squares is relatively large, then the shape of the sampling distribution is necessarily

When analyzing experimental research via the F ratio, random error and individual differences among the subjects is most clearly shown in the value of the

If the F ratio were performed on a four-group design and F were equal to 4, then t would be equal to

If a significant F ratio is obtained, then