What's the difference between the two?

LSAT DeterminedLSAT Determined Core Member
in General 204 karma
All Librarians enjoy spending time organizing books. Since Susan enjoys spending time organizing books, I imagine she's a librarian.

It is well known know that Yahoo Corporation has slashed the amount it pays in salaries by 6 percent this year. Since Jeff works at Yahoo, his salary was reduced by 6 percent.

Are these different flaws or the same?

Comments

  • DumbHollywoodActorDumbHollywoodActor Alum Inactive ⭐
    edited November 2015 7468 karma
    They are different. The first one is a classic sufficiency/necessity confusion. The second one is inferring that something has occurred to a part of an entity merely because that something has occurred to the whole entity. Perhaps the 6% salary reduction consists solely of the CEO losing half his income. Quite possible in this age of income inequality (sorry, I couldn't resist. Vote Bernie Sanders. :) ). In that case, Jeff's salary could stay the same or even increase.
  • nordeendnordeend Alum Member
    edited November 2015 349 karma
    @"LSAT Determined" I will take a stab at this and im sure others will correct if need be. The 1st makes the flaw of affirming the necessary condition which leads to zero conclusions. The second has a whole to part element and im not sure what is wrong with it. If yahoo reduced all salaries by 6% then it is valid since the sufficient condition is satisfied. Is this from a PT or problem set?
  • PacificoPacifico Alum Inactive ⭐
    8021 karma
    @"LSAT Determined" you need to get intimate with the Trainer if you haven't already.
  • Accounts PlayableAccounts Playable Live Sage
    3107 karma
    The first statement is definitely flawed:

    Librarian--->enjoys spending time organizing books. Susan enjoys spending time organizing books. Therefore, librarian. This is a common invalid reasoning form X--->Y. Y. Therefore X. The gist of why this is a flaw is that we don't know if being a librarian is the only type of person that enjoys spending time organizing books.

    The second statement isn't as clear cut. This was my diagram:
    Yahoo Corporation--->Slashed all salaries by 6%. Jeff works at Yahoo Corporation. Therefore, his salary was reduced by 6%. If you accept my diagram, then the reasoning is valid. We don't actually know if ALL salaries were slashed by 6% (it was an assumption I made in order to diagram it).

    However, given the context of the statement, I think it is flawed because it suggests a whole to part flaw. Just because salaries in general were slashed by 6%, it doesn't mean that Jeff's salary was necessarily slashed. Hope this helps!
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