Question

A researcher is interested in the effects of exercise on mental health and he proposes the following study: Use stratified random sampling to ensure representative proportions of 18-30, 31-40 and 41- 55 year olds from the population. Next, randomly assign half the subjects from each age group to exercise twice a week, and instruct the rest not to exercise. Conduct a mental health exam at the beginning and at the end of the study, and compare the results.

(a) What type of study is this? (observational or experimental study)?
(b) What are the treatment and control groups in this study?
(c) Does this study make use of blocking? If so, what is the blocking variable?
(d) poin Does this study make use of blinding?

Answer 1

The described study is an experimental study, with subjects split into treatment and control groups based on exercise. Blocking is used with age as the blocking variable, but the use of blinding is not specified.

Step-by-step explanation:

The study described by the researcher is an experimental study, not an observational study. This is because the researcher is actively manipulating a variable (exercise) to observe its effect on mental health.

The treatment group consists of subjects from each age group who are instructed to exercise twice a week, while the control group comprises subjects from each age group who are instructed not to exercise.

Yes, this study does make use of blocking. The blocking variable is age, as subjects are grouped into strata based on their age before being randomly assigned to treatment or control groups.

As for blinding, the description provided does not specify whether the participants or researchers are blinded to group assignment. Therefore, we cannot confirm the use of blinding without additional information.

Answer 2

Step-by-step explanation:

(a) The type of study described in the question is referred to as an experimental study.

(b) The treatment group is the group that exercises 2 times a week, whereas the control group is the group that does not exercise.

(c) Yes, the study under consideration makes use of blocking.

The blocking variables are 18-30-year-olds, 31-40-year-olds, and 41-55year olds.

(d) No, the study under consideration did not make use of blinding because the patients know if they are in the group that exercises or the one that doesn’t.