Deck 6: Analyzing Data When You Are Comparing Two Groups

Question 1

A test of hypothesis involving the comparison of mean scores of two distinct groups on a variable of interest that is measured at the interval level, requires the use of:

A) the dependent samples t Test
B) pearson's product moment correlation
C) the independent samples t Test
D) the one-sample t Test

Answer 1

C

Question 2

When you analyze evaluative data and you need to establish if there is statistical significance in the mean difference between two groups, the statistic you employ will be determined by:

A) the sample size
B) the structure of the data
C) the type of hypothesis
D) the study question

Answer 2

B

Question 3

When you employ SPSS to test hypothesis, the default is:

A) one-tailed test
B) statistical significance test
C) two-tailed test
D) estimation of margin of error

Answer 3

C

Question 4

The two pieces of evidence that you need for your hypothesis to be supported by your data:

A) large sample and your data must be in the hypothesized direction
B) the findings from the hypothesis test must be statistically significant
C) large sample and your data need not be in the hypothesized direction
D) your data must be in the hypothesized direction and the findings from the hypothesis test must be statistically significant

Question 5

When you report statistical significance of the mean scores of the two groups and whether the difference is statistically significant or not, you will report the values of:

A) mean and standard deviation
B) standard error and the degrees of freedom
C) the f ratio and variance
D) t and p

Question 6

Practical significance is addressed by:

A) the magnitude of the difference in mean scores between the two groups
B) the effect size
C) the magnitude of the difference in mean scores between the two groups and the effect size
D) reports from the sample

Question 7

With the independent samples t Test, the effect size is:

A) the difference in the mean scores of the two groups in the study
B) the average score of each of the two groups with the pretest scores of the groups used as a threshold
C) the number of standard deviations of difference between the two groups
D) the size of the sample in each group

Question 8

Of the advantages of reporting the effect size, the major one is:

A) it is easy to estimate the difference in mean scores
B) it is standardized
C) it is useful in comparing different studies
D) it is standardized and it is useful in comparing the effect size of other studies that may have employed different measurement tools

Question 9

An evaluative researcher is studying the impact of mindfulness training in increasing emotional intelligence, using a comparison group design and noticed that his/her study has a higher mean gain of emotional intelligence between the treatment group and the comparison group than another study that too was studying the impact of increasing emotional intelligence using a comparison group design, while using a different scale to measure emotional intelligence. What is necessary to make a meaningful comparison of your study with the other study's findings, particularly in estimating the practical significance of your study?

A) p value of both the studies
B) effect size of both the studies
C) just the gain score in the emotional intelligence of the treatment groups
D) just the standard deviations of both the studies' posttest mean scores

Question 10

When you report the findings of your study, you will report:

A) the value of t
B) the sample size
C) the sample size and the effect size
D) the value of t, the sample size, the value of p, and the effect size

Question 11

The specifications in SPSS using, "Analyze", followed by selecting "Compare means" from the drop down menu and choosing "Independent samples t Test" will allow you to:

A) find the mean difference between the pretest scores and posttest scores of one group only
B) find the mean difference between the posttest scores of one group and compare it to a threshold group
C) find the mean difference in gain between two different groups
D) compute correlations

Question 12

In the SPSS procedure for using the Independent samples t Test, the "Test variable" in the dialog box, refers to the:

A) pretest score
B) posttest score
C) gain score
D) sample size

Question 13

The output for the independent samples t Test has two lines of data and the choice of line for interpretation is determined by the:

A) means test
B) standard deviation
C) test for equality of variances
D) F Ratio

Question 14

Measuring the dependent variable in simply mutually exclusive categories such as "improved" or "not improved" for both a treatment group and a comparison group statistical significance can be established by:

A) one-sample t Test
B) independent samples t Test
C) chi square test
D) Spearman's rho

Question 15

The expected frequencies in a chi square table are:

A) those that would indicate relationship between the two variables
B) those that would indicate absolutely no relationship between the two variables
C) those that would indicate some relationship between the two variables
D) those that would indicate moderate relationship between the two variables

Question 16

Practical significance is examined, when you use chi square for dichotomous data, by comparing the proportions of people in each group who succeeded and by referring to:

A) Cramer's V
B) Fischer exact probability test
C) Proportions
D) phi coefficient

Question 17

When you have data on each person in each of two groups, with pretest and posttest measurements for each person in these two different groups, you cannot compute the gain score for each.

Question 18

When you choose to use directional hypothesis, such as "The posttest scores on the scale for depression will be less than the pretest scores on depression," you have reason to predict the outcome of your intervention in reducing depression.

Question 19

SPSS has its default setting for one-tailed test and Excel allows you to do two-tailed test.

Question 20

The understanding of the meaning of a given difference in the mean scores between two groups on the study variable is important for reaching a conclusion about practical significance of the study findings as merely stating an opinion regarding practical significance is not an acceptable way of reporting practical significance.

Question 21

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

Question 22

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.

Question 23

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.

Question 24

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

Question 25

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

Question 26

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.

Question 27

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.

Question 28

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

Question 29

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

Question 30

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.

Question 31

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

Question 32

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.

Question 33

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.

Question 34

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

Question 35

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