Official Solution:
In order to find out the effect of computer gaming on 'cognitive flexibility' – ability to switch between tasks – researchers recruited two groups having equal number of volunteers. One group played a real-time strategy game, which requires frequent decision making and high level of organising skills, while the other a life-simulation game, which does not require much memory or many tactics. The two groups played their respective games for at least forty hours over six weeks.
Each of the following may be important to know before arriving at a conclusion regarding the influence of playing computer games on cognitive flexibility except:
A. Whether professional gamers who had high cognitive flexibility played the games.
B. How many participants in each group have been playing strategy games before the experiment?
C. How was the performance of the participants on cognitive flexibility tests before the experiment?
D. How was the food habits and sleeping habits of the participants during the experiment?
E. How was the performance of the participants on cognitive flexibility tests after the experiment?
(A) CORRECT. The research is limited to the people who were participating in it - professional gamers are out of the scope of the research and hence option A is not important to be known. (Moreover, knowing whether professional games with high cognitive flexibility play the game would not help determine whether the game caused such high cognitive flexibility among those gamers or something else did.)
(B) If players in the life simulation game group have already been playing strategy games, then the experiment would not generate proper result. It may so happen that both the groups perform equally well in the cognitive flexibility tests (because their cognitive ability improved because of playing strategy games, either before the experiment or during the experiment) and thus would not reveal the differential effect of playing the different types of games.
(C) It is important to know whether the groups performed equally before the test (and also after the test) or whether one group was already better than the other before playing the games. Cognitive flexibility tests, both before the experiment and and after it, would be helpful in determining the change in the capability.
(D) It is important to establish whether sleeping habits and food habits, rather than playing the games, influenced the result of the cognitive flexibility test.
(E) It is important to know whether the groups performed equally after the test (and also before the test). Cognitive flexibility tests, both before the experiment and and after it, would be helpful in determining the change in the capability.
Answer: A