Wednesday, August 11, 2010

Assumption LSAT Logical Reasoning : Direct Logic Link

For today we'll tackle one of the most maddening--but thankfully rare--tasks, direct logic link assumption. All test prep companies have their own take on how to spot assumptions, but as per usual, here at Zen of 180 we have a slightly more discriminating classification system. There are four types of assumption questions on the LSAT; direct logic link requires to restate the positive version of a conditional from the evidence or bridge which is treated as a definite by the argument's conclusion.

Thus, the answer in direct logic link task will be an "LSAT speak" restatement of either the evidence or the bridge of the stimulus. While that sounds easy enough, the answer thus also looks like a common distractor for all the other assumption tasks! Unlike with the other assumption tasks, if you can positively identify the conditional statement within the stimulus that the conclusion requires, you can perfectly pre-phrase your answer.

To avoid the issues caused by the huge differences in the approach for this task as opposed to the rest of the assumption strand, we advise our clients to treat all assumption question stems as though they had a gap between the evidence and conclusion.  Thus, you must constantly be on the lookout for conditional statements while reading assumption task stimuli.

The difference between prephrasing the gap and prephrasing the answer is similar to saying, "I need to get across the river here" and "I need to drive across the one-lane wooden bridge." The former prephrase will allow you to consider any answer that accurately links across the--in this case literal--gap, while the latter will be too specific for many test takers to find the credited response translated into LSAT speak.

At first blush, such distinctions between executive boards and Executive Directors or between gaps and answers can appear to be inconsequential; however, the LSAT gets plenty of test takers to gloss over a crucial definition shift between evidence and conclusion. This test is not kind to careless readers, and the specificity of language employed is very different from everyday language.

The example from the October 1996 sample PrepTest is a perfect example of that required level of specificity, where the conditional is "when" rather than "if" and the answer choice is the contrapositive of the conditional.  Mean, we know.

The question stem for this strand is fairly easy to identify, and since direct logic link assumptions are so rare, be sure to first approach them as you would a definition assumption task.  Be sure to actively read the stimulus for the conclusion, the key evidence, and actively fact-check the conclusion to find disparities between the two.

We're in the process of analyzing the older PrepTests for the different assumption tasks, but we do know how often it has been asked on modern LSATs. It averages 2.6% of the points on a modern LSAT, but there have been a couple PrepTests with no direct logic link assumptions.
    12 times
    on LSATs since 2007
    2.6% of LR
    (1 per LSAT, range 0-3)
    ?% growth from pre-2007
We'll update this page after we're through analyzing all the older PrepTests for this particularly tricky assumption task.  Meanwhile, always keep an eye out for the conditionals; it's a very easy task once you know what to look for!