Question

(1) Cholesterol levels of 63 year old adult women who exercised 3 or more times per week are compared to those of 63 year old adult women who exercised no more than once a week. This an example of

A. a comparative experiment
B. an observational study  
C. an uncontrolled experiment
D. a case- controlled study

(2) A market research company wishes to find out whether students prefer brand A or brand B of instant coffee. A random sample of students is selected, and each one is asked to try brand A first and then brand B (or vice versa, with the order determined at random). They then indicate which brand they prefer.

(a) This is an example of

A. block design.
B. a matched-pairs experiment  
C. stratified sampling design.

Answer 1

1) This is a comparative experiment because we are comparing two groups.

Option A is correct.

2) The same subjects are checking brand A and B. Hence, this is an example of a matched-pairs experiment.

Option B is correct.

​​