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 the volunteers already knew the rules of the games before the experiment?
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. What was the ratio of male to female in each group?


(A) Correct. The result of the experiment does not depend on whether the volunteers knew the rules beforehand.

(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 or one group was already better than the other before playing the games.

(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 establish whether gender bias, rather than playing the games, influenced the result of the cognitive flexibility test. It may so happen that one gender naturally performs better than the other in cognitive flexibility test.


Answer: A
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In the explanation of the answer C you say "whether the groups performed equally before the test or one group was already better than the other", but it doesn't say anything about it. Is says about HOW was the performance measured. Though it is still important, since you have to compare the level before the experiment with results, measured by the same method, but after the experiment.

Of course. Per your reasoning knowing the performance before is one important thing. Knowing the performance after is another. The question asks which is NOT important to meausure. As it is ONE OF THE THINGS that "may be" important ( though you would require another important parameter, i.e. the performance after) it cannot be the right answer - i.e. it cannot be an unimportant thing too measure.

That's true; I agree, that the choice is incorrect. I wanted to point out, that the explanation is not correct.

Why do you say so? The explanation clarifies why it is important to know the performnace BEFORE the test...

"...or one group was already better than the other before playing the games."

How can the option E not the correct answer???The explanation is not yet clear.Can you plz elabprate more??

One example may clarify your query:
Suppose Group A, which played real-time strategy game, consists of females and group B, which played life-simulation, consists of males. Now suppose we find that group A performs better on "cognitive flexibility" test. We shall yet not be able to conclude that the people who play real-time strategy has higher cognitive flexibility because it may so be the case that females are naturally better in cognitive flexibility - thus playing RTS games may not be the reason that group A performed better in cognitive flexibility.

I think this is a poor-quality question and I don't agree with the explanation. Lets see if knowing option B helps to arrive at any sort of conclusion or not.

Question: How many participants in each group have been playing strategy games before the experiment?

Say the Answer is 19 in group 1 and 27 in group 2. Ok so? How does this help in arriving at the conclusion regarding the influence of playing computer games on cognitive flexibility?

Unless we know the total number of participants in each group, we will not be able to use the data on the number of participants in each group who have been playing strategy games before the experiment.

Poor Quality choices.

You have a point - the question has been slightly modified to take care of this. Why do you feel that the other choices are of poor quality?

In a game, especially strategy game, knowing the rule is extremely important and brings lots of competitive advantage. How can he say "the result of the experiment does not depend on whether the volunteers knew the rules beforehand"

It is not required to know the rules "beforehand". When the player came to know the rules does not matter -just that he should know the rules when the game starts.

I am not convinced with the OA.
I think E should be the answer. The passage is no way indicative of the fact the men and women may perform differently .
You will have to bring outside knowledge to assume so and i don't feel convinced that this would be Sun and Moon kind of universal truth.
Universal truth is that which cannot be challenged .
what if the experiment involved Men and women who were equally skilled .We cannot assume that men and women involved were typical representatives of their
gender. In this case answering the last question doesn't necessarily help with the conclusion.

Any thoughts on this?

I also dont agree with the explaination. First it has been written in a very deceptive langauge that beforehand means just before the experiment. Secondly the effect of gender on the cognitive ability is too heavy a assumption. And in cr u r not allowed to assume that much
Finally i want to tell one thing that we cant change our concepts too many time. This is why students suffer much in cr. I again request the experts to please comment on this reply. How can one say that gender is influencing the abilties whereas the rules of the game do surely.
Even if we compare the options . E assumes too much but a assumes little

It is required that the two groups are composed of comparable members in order to arrive at the conclusion. Sex (like age) may be an important factor in the fundamental skills of the brain. In order to eliminate the sex bias because of this factor, it is required that the groups are composed of equivalent M:F ratio.

The word "beforehand" means before the experiment started. It does not matter whether the rules were known just before the experiment started or long before the experiment started.

Yes I agree with you.But don't you think that to reach that conclusion you need outside thinking or assumption.The question doesnot say anything about gender biasing influemcing cognitive thinking.In fact I think that gmac will never make an option as right answer choice that provokes such thoughts.

Hi Experts,

Choice A - Whether the volunteers already knew the rules of the games before the experiment?

lets say there are two people who are participating.
One knows the rules of the game really well and the other has no clue about the rules before the start of the game.
It does give player one an advantage over player two.

Now lets say there were 100 volunteers, and 50 knew the rules of the game beforehand and all 50 of them are in the same group, then it is likely that this group may perform better.
I now assume that you will explain that knowing the rules may have no bearing on the performance in the game, but this logic seems too far fetched to me.

Choice E - You say that gender can influence the outcome.
So if gender bias can influence, then so can prior knowledge of the game rules influence the performance?

Please can you clarify

While the reasoning seems right, I have an issue with gender bias option - E. I don't think GMAT will ever convey even indirectly through option that there is the difference between the cognitive ability of men and women. That's a highly debatable topic.

Even I'm not convinced with the OA. Gender biased cognitive ability doesn't sound 'ok' to accept.

Even I am not convinced with OA. Ideal answer should be E, as there is no information on passage regarding impact of gender on experiments.