Question

A swimming coach wants to test the effect of diet on swimmers’ stamina. He wants to compare between diet A – sugar and fat rich diet, and diet B – low sugar and fat diet. The outcome variables is the length of time swimmers can keep swimming after being on the diet for three days. (2 points)

a. Design a within-subject study to compare the two diets

b. Design a matched-subjects study to compare the two diets. Use the swimmers’ BMI as the grouping variable.

Answer 1

a. for a within subject design the same group serves as the subjects for both the experiments. hence we randomly select agroup of swimmers and determine their swimming capacity before the treatment then we treat them on diet A and [measure the capacity and later we treat them on diet B and measure the capacity. the results can be copared and the outcome can be analysed.

b. for matched subject study we need to divide the selected subjects into 2 groups and go on with the study. the groups should be randomly divided such that the BMI is kept in mind i.e. all the high BMI people shouldnt be in one group and nor all the low ones. for this we need to select the group and record the performance without treatment and then divide it into 2 groups of equal numbers. one group will go through diet A and the oother group will go htrough diet B and the performance of both will be recorded and compared. the conclusion can be made on the basis of comparison of average performance nof both the groups.