# The Key to GMAT Critical Reasoning: Reading to find the missing link Part 2

Unfortunately, the missing links on the GMAT are much more subtle and difficult to find than the blue dress example discussed in the previous post. However, with a lot of practice, critical thinking and active reading, it will start to come naturally.   Let’s take a look at a more realistic GMAT type question:

At Bryowan University a group of college students participated in a sleep study. Half of them slept a full 8 hours a night for a week, the other half slept for a total of 8 hours, but were woken up two to three times during the night each night, during that week. The half that slept the full 8 hours straight performed better, on average, on a logical reasoning exam than the half whose sleep was interrupted.   Therefore, people have the best brain function when they sleep for a full 8 hours, uninterrupted.

This argument tries to use the results of the study to prove the conclusion that people have the best brain function when they sleep for a full 8 hours uninterrupted. There are actually quite a few missing links here, let’s look at a few:

• First, you have the sample of people. The people who were tested were all college students who, on average, are aged 18-22. However, the conclusion is about people in general, which is a leap on logic. If something affects people 18-22 in a certain way, it doesn’t necessarily mean that it will affect all people in that way.
• Another leap in logic is the assumption that a higher score on a logical reasoning exam means that the person has a higher brain function. This might not necessarily be the case. For example, people may perform better on logical reasoning, but poorer on everything else, thus having an overall lower brain function.
• Another problem with this argument is the use of the word best. Always be wary of words like best, most or any other type of extreme language. The study discussed in the argument only tested two different sleep scenarios. Just because one is better than the other, doesn’t necessarily mean that it is the best.

After you have asses the problems with the argument, you can use them to find the correct answer in various ways, depending on the question type.

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Eliza Chute

I was always just an average student, but with the right course prep I was able to score a 770 on my first try. I had to wade through a lot of material to find what was right for me, but luckily for you I've done all the research for you! See more on my GMAT courses page.