Question

A researcher wishes to study the effect of drinking alcohol on players' scores in a video game. 180 people (60 females and 120 males) have volunteered to participate in the study. The treatments he would use will be 0, 1, 2 and 3 cans of 5% beer (355ml each) consumed 15 minutes before the start of the game. The participants' scores in the video game will be recorded

Select one:

a. The researcher should use randomized block design with two blocks for each treatment.

b. The researcher should perform observational study.

c. The researcher should use completely randomized design.

d. The researcher should use randomized block design with 4 blocks for each treatment

e. The researcher should use a matched pair design, pairing a male with a female volunteer.

Answer 1

Here, the researcher is interested in studying the effect of drinking alcohol on players' scores in a video game, where, he uses 4 treatments and has also considered the variable - gender too. This is because, if he wishes to eliminate the additional effect of gender along with alcohol on the players' scores, he must control for the variable gender, by ensuring that each treatment has an equal number of men and women. Hence, we may consider the two groups of Gender - Male and Female as Blocks in the design. Hence, the appropriate design here would be:

a. The researcher should use a randomized block design with two blocks for each treatment.

b. This would not be an observational study since the researcher actively involves himself and assigns the treatment to the subjects following a particular design and not merely observes and records the outcome.- An observational study would not be appropriate here.

c.Since he wishes to control the effect of Gender, a completely randomized design would not serve his purpose.

d. As mentioned at the start, for 2 groups of the blocking factor, this would not be appropriate.

e. Here, there are more than 2 treatments and also, the number of males and females in the sample is not equal, to form pairs. Hence, this design would not be appropriate here.