Question 1

When the difference in gain scores may be identical in two studies, the effect size is bound to be identical.

Accepted Answer

Effect size takes into account not only the difference in gain scores but also the variability within each study's sample, so even if the difference in gain scores is the same, the effect size may differ if the variability in one study's sample is greater than the other's.

Question 2

For a study to have an impressive effect size, if the variance in scores is high, the magnitude of difference in mean scores between the two groups must be small.

Accepted Answer

For a study to have an impressive effect size, the magnitude of difference in mean scores between the two groups must be large, regardless of the variance in scores. This means that a small effect size can be impressive if the difference between the means is large enough, even if the variance in scores is high.

Question 3

In comparing the scores of two groups, using independent t Test in Excel, you will enter the gain scores of each of your two groups and you will not enter either the pretest or posttest scores.

Accepted Answer

The independent t-test in Excel requires the gain scores (difference between posttest and pretest) for each group to compare the means, not the raw pretest or posttest scores.

Question 4

When you report your study findings you are not required to report on whether your hypothesis was supported or not, by the findings.

Accepted Answer

It is important to report whether your hypothesis was supported or not by your findings in order to provide a clear and accurate summary of your study.

Question 5

An effect size of two is considered a small effect size.

Accepted Answer

An effect size of two is considered a very large effect size, not a small one. Generally, an effect size of 0.2 is considered small, 0.5 is considered moderate, and 0.8 or higher is considered large.

Question 6

In the SPSS procedure for using the independent samples t Test, the "Grouping Variable" refers to the specifications pertaining to the two groups used in the study.

Accepted Answer

The "Grouping Variable" in the independent samples t test refers to the variable that specifies the groups being compared in the study. This variable must be dichotomous, meaning it has only two categories or groups.

Question 7

After conducting the independent samples t Test, when you notice that the treatment group's mean is higher as you hypothesized, it is not necessary to know whether the higher mean score for the treatment group is statistically significant.

Accepted Answer

It is important to determine whether the difference in means between the treatment group and control group is statistically significant in order to confidently conclude that the treatment had a statistically significant effect.

Question 8

The output from the SPSS analysis provides you with the effect size.

Accepted Answer

The answer of The output from the SPSS analysis provides...

Question 9

In reporting the findings of your independent samples t Test, it is sufficient to report the value of t and the sample size.

Accepted Answer

In addition to reporting the value of t and the sample size, it is also important to report the degrees of freedom, p-value, and any relevant descriptive statistics (such as means and standard deviations). Without these additional pieces of information, the results of the t-test may not be fully understandable or interpretable.

Question 10

When you compare two groups and when you have a dichotomous dependent variable, you can employ either the special Excel file or SPSS, for the examination of the relationship between the two variables.

Accepted Answer

Both Excel and SPSS can be used for examining the relationship between two variables when one of them is dichotomous.

Question 11

Chi square is appropriate for very small samples even when the data have most of the cells with "expected frequencies" less than 5.

Accepted Answer

Chi square test should not be used for samples with small expected frequencies less than 5 as it may lead to inaccurate results. A better alternative for small sample sizes would be Fisher's exact test.

Question 12

When you employ the chi square statistic for dichotomous data, you should report the table showing the data, the value of chi square, and the phi coefficient.

Accepted Answer

When reporting the results of a chi square analysis with dichotomous data, it is important to provide the table showing the observed and expected frequencies, the value of chi square, and the phi coefficient (or other appropriate effect size measure).

Question 13

Please explain the importance of statistical and practical significance in evaluative research, with special reference to the two group comparison design using dichotomous nominal variables.

Accepted Answer

The answer of Please explain the importance of statistical and...

Question 14

Under what conditions would you employ the Fisher exact probability test?

Accepted Answer

The answer of Under what conditions would you employ the...

Question 15

Please explain to an evaluative researcher, the procedure for computing chi square for two groups on a dichotomous variable using SPSS.

Accepted Answer

The answer of Please explain to an evaluative researcher, the...

Quiz 6: Analyzing Data When You Are Comparing Two Groups