Deck 12: Glm 1: Comparing Several Independent Means

Question 1

Under what conditions would planned comparisons be used?

A) When specific hypotheses have been generated prior to the start of the experiment
B) When specific hypotheses have not been generated prior to the start of the experiment
C) When homogeneity of variance is violated
D) When homogeneity of variance > .05

Answer 1

When specific hypotheses have been generated prior to the start of the experiment

Question 2

If the critical region for a test of hypothesis is F > 9.48773 and the computed value of F from the data is 0.86 then which of the following is correct?

A) The null hypothesis should be rejected.
B) The alternate hypothesis is two-tailed.
C) The significance level is given by the area to the right of 9.48773 under the appropriate F-distribution.
D) The significance level is given by the area to the left of 9.48773 under the appropriate F-distribution.

Answer 2

The significance level is given by the area to the right of 9.48773 under the appropriate F-distribution.

Question 3

What does the term 'familywise error rate' mean?

A) The probability of a Type II error occurring
B) The error rate across statistical tests conducted on different experimental data
C) The error rate across statistical tests conducted on the same experimental data
D) a and c

Answer 3

The error rate across statistical tests conducted on different experimental data

Question 4

What is the definition of 'mean square''?

A) A sum of squares divided by its degrees of freedom
B) The square root of the mean
C) The square of the mean
D) A table of means with four cells

Question 5

A researcher wanted to see the effects of different learning strategies. A control group simply read the book Discovering Statistics (book), a second group read the book and completed the 'end of chapter exercises' (book and exercises), and a third group read the book, did the end of chapter examples and also completed the web materials (all activities). The researcher predicted that the all activities and book and exercises groups would perform better than the book group on a subsequent test, but that the book and exercises group would do worse than the all activities group. Which coding scheme would test these hypotheses in a set of planned comparisons?

A)
B)
C)
D)

Question 6

What are post hoc tests used for?

A) When there is a large Type I error
B) When there are no specific hypotheses before the experiment
C) When the familywise error is large
D) None of the above

Question 7

The total variation in response, assuming no bias, is due to error (unexplained variation) plus differences due to treatments (known variation). If known variation is large compared to unknown variation, which of the following conclusions can be drawn?

A) There is no difference in response due to treatments.
B) There is a difference in response due to treatments.
C) The treatments are not comparable.
D) The cause of the response is due to something other than treatments.

Question 8

In a simple analysis of variance problem, which of the following is an estimate of the variance of individual measurements (after the various effects have been accounted for)?

A) MS(between)
B) MS(within)
C) MS(total)
D) None of the above

Question 9

Consider the table below. If all samples sizes are equal then the study used___? Analysis of Variance

A) 4 samples of size 10
B) 5 samples of size 10
C) 4 samples of size 9.
D) 5 samples of size 9

Question 10

A psychologist was looking at the effects of an intervention on depression levels. Three groups were used: waiting list control, treatment and post treatment (a group who had had the treatment 6 months before). The change in depression levels over the time of the treatment was recorded (although bear in mind that only the treatment group actually got any treatment during this time). The SPSS output is below. Based on this output, what should the researcher conclude?

A) The treatment groups did not have a significant effect on the change in depression levels, F(2, 26.44) = 4.35.
B) The treatment groups had a significant effect on the change in depression levels, F(2, 35.10) = 5.11.
C) The treatment groups had a significant effect on the change in depression levels, F(2, 45) = 5.11.
D) The treatment groups did not have a significant effect on the change in depression levels, F(2, 45) = 5.11.

Question 11

A Bonferroni correction is when

A) You apply a criterion for significance based on the usual criterion for significance (.05) divided by the number of tests performed.
B) You divide the F-ratio by the number of tests performed.
C) The degrees of freedom are corrected to make the F-ratio less significant.
D) The error in the model is adjusted for the number of tests performed.

Question 12

An experiment was conducted as a one-way factorial design with K sample means, each based on n scores. What is the number of degrees of freedom for the between mean squares?

A) n - 1
B) K - 1
C) n - K
D) (n - 1)(K - 1)

Question 13

In the table below, what is the likely interpretation? Analysis of Variance

A) The alternative hypothesis is rejected.
B) The null hypothesis is rejected.
C) Not enough information.
D) The null hypothesis is accepted.

Question 14

Which of the following is not considered a standard contrast in the SPSS environment?

A) Orthogonal
B) Non-orthogonal
C) Polygonal
D) Polynomial

Question 15

When variances across groups are unequal, which of the following is not an appropriate course of action?

A) Use Welch's F-ratio.
B) Use Games-Howell post hoc tests.
C) Transform the data.
D) Use Friedman's ANOVA.

Question 16

In a study of the influence of yogurt consumption and immunity (Van de Water, Keen, & Gershwin, Journal of Nutrition, 1999) there were three study groups per age group (young adults and senior adults). Live-culture yogurt, pasteurized yogurt and control (no yogurt) were given to each age group in portion sizes of 200 grams per day for 1 year. Under what conditions would ANOVA be violated?

A) When sample sizes are large
B) When sample sizes are unequal
C) When sample sizes are small
D) When there are different samples that have small variances

Question 17

What kind of trend does the following graph show?

A) Linear.
B) Quadratic.
C) Cubic.
D) Quartic.

Question 18

Post hoc tests were run using the data below. Based on the output for these tests, what should the researcher conclude?

A) The treatment group was significantly different from the post-treatment and control groups, and the post-treatment group was significantly different from the control group.
B) The treatment group was significantly different from the control group but not the post-treatment group, and the post-treatment group was not significantly different from the control group.
C) The treatment group was significantly different from the control group but not the post-treatment group, and the post-treatment group was significantly different from the control group.
D) The post hoc tests are inconclusive.

Question 19

In an experiment to determine the effects of low-dose analgesia versus high-dose analgesia in arthritis sufferers, the following findings are reported: 'there was a significant effect of medication A (low-dose analgesia) on pain control F(2, 18) = 8.14, p < .05, ω = .72'. What does this tell you about the result?

A) That the probability of a patient suffering pain with low-dose analgesia (medication A) is high
B) That the probability of a patient suffering pain with low-dose analgesia (medication A) is low
C) That low-dose analgesia (of type medication A) is unsuitable in controlling the pain for sufferers of arthritis
D) That low-dose analgesia (of type medication A) is highly suitable in controlling the pain for sufferers of arthritis

Question 20

Levene's test tests whether

A) Data are normally distributed.
B) The variances in different groups are equal.
C) The assumption of sphericity has been met.
D) Group means differ.

Question 21

When would you use the Kruskal-Wallis test?

A) When data are normally distributed
B) When data are not normally distributed
C) When assumptions have not been violated
D) None of the above