Brief write-up on assumption questions.

magickware
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Joined: Sun Nov 04, 2012 1:27 pm

Brief write-up on assumption questions.

Postby magickware » Wed Aug 14, 2013 1:31 am

So, earlier today my brother recommended to me a method of studying that I never really thought of. Basically, you more or less write down everything that you know about a particular subject, with the goal that you're explaining it exhaustively. It's not regurgitating the information in your head because you need to write it in a manner that makes sense. So, you cannot merely write down the plot-line for Hamlet; you need to explain the relationships and the complexities of the play itself.

I did this for just basic assumption questions today, and I found it to be the most enlightening way of actually reviewing how much I know the subject. It's far better than merely rereading the assumption chapter in PS or MLSAT, because I'm constantly vetting what I'm writing down against what I know, and trying to make sense of it. It helped even more that I realized that I needed to make questions up (albeit really simple ones) so that I can actually explain some of the concepts. It's by no means exhaustive, but I just found it to be a fun and good exercise, and I wanted the LSAT pros to see whether it makes sense or not.

I plan on doing it for the rest of the question types. If nothing else it's a great way for me to actually see whether I know as I think, and it keeps me honest and real about my base of knowledge. Just doing this brief write-up for general assumption questions made me realize that I don't know as much as I thought.
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--Assumption family questions
All assumption family questions have their basis on the form of an argument. That is, they focus on the premises/statements and conclusions that make up an argument. Specifically, assumption family questions focus on the unstated assumptions that exist within the argument.

An example-

Harry is a living being. All living beings are an organism. Therefore, Harry is an organism.

In the above statement, we are given two statements/premises, and a conclusion based upon the two statements. No assumption is required in the above statement, as there are no unstated gaps between the statements and the conclusion.

Say that we took out one of the statements though.

Harry is a living being. Therefore, Harry is an organism.

Here, we are given one statement, and then a conclusion that is based upon said statement. However, we do not know how we can get the conclusion that “Harry is an organism” solely based upon the statement that “Harry is a living being”. If we accept that the argument above is true, then we can only make the assumption that “Living being” and “Organism” are connected in some manner or, more specifically, that “all living beings are an organism”

The above statements rely on conditional logic. Here is an argument that doesn't rely on conditional logic.

The American Heart Association have recently released a statement that consumption of saturated fat does not, in fact, have any significant impact on your cardiovascular health. The American Heart Association is the best authority regarding cardiovascular health. Because we should always follow the advice of the best authority for any given topic, we can now safely disregard anyone who claims that consumption of saturated fat has a significantly negative impact on your cardiovascular health.

In the above argument, we're told that “we should always follow the advice of the best authority on any given topic”. So, since the AHA is the best authority, we should follow their advice. There is no inherent assumption required of us to make the argument work.

Now, imagine if we took something out.

The American Heart Association have recently released a statement that consumption of saturated fat does not, in fact, have any significant impact on your cardiovascular health. The American Heart Association is the best authority regarding cardiovascular health. We can now safely disregard anyone who claims that consumption of saturated fat has a significantly negative impact on your cardiovascular health.

With the removal of the “we should always follow the advice of the best authority for any given topic”, we no longer have any particular reason why we should care that the AHA is the best authority regarding cardiovascular health.

Therefore, it is not necessary to make the implicit assumption so that the conclusion in the above argument works. There are a variety of assumptions that can be made, but the most obvious one in his particular example is the sentence we removed.

P-AHA released statement that the consumption of saturated fat doesn't have any significant impact.
P-AHA best authority regarding cardiovascular health.
C-We can now safely disregard anyone who claims that the consumption of saturated fat has a negative, significant impact on your cardiovascular health.

A couple possible assumptions-
-We should always follow the advice of the best authority.
-Statements made by the best authority always trumps statements made by other organizations.

Etc.

The above two examples gives us a hint on the common formats of assumption questions.

The first example is one comprised of conditional statements. Given how conditional statements work, there tends to be a big concept word that is the key in the sufficient->necessary. The flow of logic within successive conditional statements mean that each big concept word must be connected to one another in some form. Therefore, any new big concept word that is introduced in the conclusion, but not present in any other parts of the premises, must necessarily become a word of interest.

To be more concise though, simply create the conditional statements and look for the missing/new term.

As in the first example-
P-Harry->living being
C-Harry->organism

The second example is comprised of a series of ideas that are related to one another in some form. Thus, there again are big concept words that should be noted, but in this case they don't necessarily help as much as in the conditional logic example above, simply because we cannot break it down into core ideas as easily.

The best I could do was-

P-AHA released statement that the consumption of saturated fat doesn't have any significant impact on cardiovascular health.
P-AHA best authority regarding cardiovascular health.
C-We can now safely disregard anyone who claims that the consumption of saturated fat has a significantly negative impact on your cardiovascular health.

We're simply not sure what big concept words we should focus on. Do we focus on cardiovascular health? AHA? Saturated fat? Thus, we should look at what the conclusion says- “we can safely disregard anyone...”, but the immediate question that should come up in your mind is “Why? Why can we safely disregard anyone who isn't the AHA?”

And this brings us to the crux of all assumption family questions. You know that there is a problem, and that you MUST find/solve said problem. In the necc/suff assumption questions, you're looking for the assumption that is REQUIRED to bridge the gap between the premises and the conclusion, so that the argument actually makes sense.

This mentality keeps you on a constant state of alertness as you go through the questions instead of mindlessly reading the stimulus, and forces you to constantly question what the conclusion says. Chances are, whatever you question will be the actual issue.

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