Question

9 additional students were used as a control group. Each of these students had pre and post ratings made at the same time as the pre and post ratings for the treatment group. However, the control group did not attend the lecture - slide demonstration as did the treatment group. The researcher hypothesized that improvement ( pre and post) scores for the treatment group would be higher than improvement ( pre and post) scores for the control group. What statistical test is appropriate for testing this hypothesis?

Answer the following questions:

1. What type of research question is being asked?
2. What is the level of measurement of the response variable?
3. What is the research design (1, 2, 2+ groups)?
4. Were samples independently selected or were they matched?
5. What is the appropriate statistical test for analysis?

Answer 1

ANSWER:

Given that,

a)

The type of research question is Comparable since we are comparing the improvement ( pre and post) scores for two groups.

b)

The response variable is improvement ( pre and post) scores which is a continuous numerical variable. Thus, the level of measurement of response variable is ratio.

c)

Since there are two groups involved (treatment and control group), research design is 2s group.

d)

Since the students in both the groups are independent, they were not matched.

The samples were independently selected.

e)

For test of significance of mean difference of two independent samples, we would use independent samples t-test.