Thursday, March 8, 2012

Logical Reasoning: Justify Task

Today we'll introduce one of the tasks from the principle strand of the LSAT logical reasoning section: justify.

This Zen task is one of the more difficult to recognize as it can easily be conflated with its other principle strand counterparts as well as with the strengthen task. Whereas the other principle tasks as you to match examples with principles or vice versa, justify requires you to identify a qualitative premise that covers at least the stimulus' argument.

On a modern LSAT, a common question stem is:
Which one of the following principles, if valid, most helps to justify the [stimulus'] reasoning?
Often, however, a justify answer will obviously apply to many more situations than just the one(s) presented in the stimulus; this "scope" difference can be confusing for test-takers, who are punished for thinking broadly in almost every other logical reasoning task.

We've decided to give JT the benefit of the doubt on needing justification, despite his insistence on "acting."
As with all principle standards, the correct answer to a justify question will map onto the evidence presented in the stimulus including all the relevant actors, relationships and degrees of certainty. However, justify requires the testtaker to pay much more attention to the stimulus' conclusion (indeed, other principle standards might only be a collection of evidence with no conclusion), as the correct answer will be a generality that provides some affective premise for the conclusion. Thus, the same strategy of identifying actors, their relationships, and degrees of certainty that works for the extrapolation strand will also apply for this task.

For example, a stimulus from the point of view of a law clerk might provide that:
A judge should apologize to me for lying to me because the judge has already apologized to the lawyers on the case for telling them the same lie.
The correct justify answer could be framed in varying levels of generality, from "If a lier apologizes to one person for lying, he should apologize to someone else who finds out he was lying," to "Everyone should apologize for lying."

Distractors for this argument could include:
  • Conflating the relationship "should apologize" with being "good to apologize"
  • Incorrectly limiting the scope of the relationship, such as saying that a lier should apologize only if both of those lied to deserve the apology.
    • Note that the stimulus doesn't need this to be the only reason a lier should apologize, nor does it explain why the clerk deserves an apology.
  •  Conflating the relationship "should apologize" with "able to apologize"
  • Incorrectly negating the argument, i.e., stating that a lier does not need to apologize unless all who have been lied to can receive an apologize.