Probably the single most difficult question type of the GMAT critical reasoning and /or reading comprehension questions is the Assumption. And that is strange considering that ‘assuming’ is quite a common word in the parlance of most people. Stop assuming things. This is an assumption. How can you assume this? These are but a few of the commonly mouthed phrases in most conversations and so my guess is that most of us do know what ‘to assume’ means. Or am I only ‘assuming’ that just because someone can use the word, he knows what it means and what its dynamics are in reasoning?
When it comes to tackling this question on the GMAT test, most are clueless as to what needs to be done. My effort here is to first share with the reader a coherent and very simple definition of Assumption and then to explain 2 effective strategies for solving the question.
DEFINITION: An assumption is what the writer takes for granted, believes is too obvious to merit a mention, and hence omits including in the facts provided en route to a conclusion. The result is that the conclusion goes a little beyond the capabilities of the facts and even carries an entity that is ‘extra’ to what is mentioned in the given facts. In other words, the facts as they stand do not justify the conclusion.
There is something missing in the facts and hence there is a ‘gap’ between the facts and the conclusion and so the writer seems to be jumping to a conclusion rather than arriving at it logically.
REQUIREMENT: What needs to be done is fairly simple. We need to pick an answer that can serve as that missing detail/fact, that can fill the ‘gap’ and that can allow for a logical transition from the facts to the given conclusion.
STRATEGY: The ultimate objective of selecting an answer is to be able to provide an additional premise (simply called the additional fact/detail) which when added to the given facts will serve to strengthen the given conclusion.
There are many ways to achieve the objective of an Assumption task. One way is to work by word identification. Check what it is in the conclusion that is unique to it and has not been mentioned in the entire set of facts. This ‘word’ is the extra entity that is making the conclusion overstep the potential of the facts. Once spotted, this ‘word’ – say Q- allows us to eliminate answer choices that do not carry it; after all if we are to conclude about Q, we must select as the additional premise an answer that carries Q! If there are say 2 answer choices that fit this requirement, then we need to pick that of them that better serves the purpose of leading to the conclusion.
Another way to solve the Assumption puzzle is to eliminate reverse causality or sometimes even outside causality. For example, if the conclusion is that X causes Y (because they have been observed together), then one assumption is that Y does not cause X (REVERSE CAUSALITY) and the other is that Z does not cause Y (OUTSIDE CAUSALITY). Both possible paths lead to the prime objective of endorsing the given conclusion that X causes Y.
This said, it would be in the fitness of things to leave you chewing upon what I have just shared so that you can actually use the methodology to solve the next Assumption question you come across. I’ll be back next week with an Assumption question for you and some more tips on the Critical Reasoning bouncer- THE PARADOX!