Question

A study was conducted to compare the effects of three different drugs on the alleviation of anxious depression in non-psychotic patients. Twelve non-psychotic patients, all suffering from moderate to severe depression and anxiety, were grouped according to initial level of severity. Patients in each severity level group were randomly assigned to the three treatments (drugs). At the end of the experimental period, a combined anxiety and depression score as determined by the MMPI and Taylor Manifest Anxiety Scale was recorded for each patient. The researcher hypothesizes that there is a difference in average anxiety/ depression scores for the three drugs.

The data are as follows:

Initial Severity Level------------ Drug A--------------- Drug B------------------- Drug C

1 ---------------------------------------35----------------------30----------------------- 25

2 --------------------------------------40---------------------- 25----------------------- 20

3---------------------------------------25-------------------- - 25----------------------- 20

4 --------------------------------------30---------------------- 25---------------------- -25

What statistical test is appropriate for testing the researcher's 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

1). The research question is to compare the means of three types of drugs. i.e.,

Is there any difference in average anxiety/ depression scores for the three drugs.

2). The level of measurements is recorded on a continuous scale.

A combined anxiety and depression score as determined by the MMPI and Taylor Manifest Anxiety Scale was recorded for each patient.

3). The research design is more than two groups.

4). The samples are independently selected. since from the given information,

Patients in each severity level group were randomly assigned to the three treatments (drugs).

5). The appropriate statistical test is one-way ANOVA. which can be used to test the equality of means.