PT69.S4.Q16 - salespeople always steer customers

blackhawksfan

http://7sage.com/lsat_explanations/lsat-69-section-4-question-16/

Hey test-takers! If you have PT69, care to discuss this question with me?

Upon review, the flaw is glaring and answer choice (B) makes sense.

During the timed test, I chose (C) and now I still can't see why the author did not make that error. H/she went from "salespeople" (whole) to "salespeople in major health stores" (part). This was the reasoning used to the reach the conclusion, so why is it not right to attack it?

Thank you!

David Wayne

No such flaw was committed; the argument's premises indicated that all salespeople who work for commission direct their customers towards those items that allow them to make the highest possible commission. The argument then indicates that all salespeople who work in major health stores work on commission. Essentially, two criterion are sufficient to indicate you direct your customers towards only those items that give you the highest commission; you have to be both a salesperson, and you have to actually be a salesperson who works on commission. The salespeople at the major health stores, as indicated by the argument, satisfy both of these conditions; they are salespeople, and they work on commission.

The argument has a sort of pseudo intermediate conclusion, in that it successfully proves that the salespeople in major health stores do direct their customers towards items from which they derive commission. Often, a flaw can be committed in the premises supporting an intermediate conclusion, and so its always prudent, when analyzing arguments with intermediate conclusions, to analyze both the support structure between premises and intermediate conclusion, and support structure between intermediate conclusion and main conclusion. In this argument's case, the support fails between the intermediate and main conclusion. But there is no question that the argument has successfully proven that salespersons in major health stores can correctly be designated as salespeople interested in directing customers towards items from which they derive commission.

blackhawksfan

Hi David Michael, thanks for your excellent response! I really appreciate the detailed message.

I definitely see the first sentence of the stimulus as "A ----> B" [salespeople ---> steer customers toward products from which they make their highest commision]

So, all salespeople in major health stores (let us call them C) help us reach
C ---> A ---> B
(salespeople in major health stores ---> salespeople ---> steer customers . . .)

So there is no flaw. But IF it had said, 'Salespeople generally tend to steer customers toward products from which they make highest commissions' and from that conclude that the salespeople in the health stores do the same, would that be a whole to part flaw? Even then, I'm not sure it would because the main conclusion is strictly concerned about the quality of products being inaccurate.

David Wayne

Your argument doesn't commit the characteristic whole to part flaw the LSAT commonly employs. It does commit another flaw, that of inappropriately interpreting what the term 'generally' means.

Having done a great deal many of the LSAT arguments from the released preptests, however, i have come to realize that the LSAT commits this flaw in a very standard way that seldom varies from test to test.

The way to tell whether the flaw is committed is whether the possibility exists that parts of a whole give that whole its property. For instance, a basketball team that is highly skilled is not necessarily comprised of highly skillful players, for the possibility exists that the team's skill is derived from the interaction amongst its constitutive parts. That's the key; whether the possibility exists that a whole's parts are what give the whole a property. Conversely, if i tell you a table's constitutive parts are all made of wood, and then conclude that the table is made of wood, i would not be committing a part to whole flaw, because the table's being wooden is not dependent upon the interactions between the constitutive parts having a certain quality.

So in your argument, the fact that salespeople GENERALLY tend to steer customers isn't really in whole to part territory. The word generally (which, incidentally, is used interchangeably with the word USUALLY on many LSATs) is defined by the dictionary (and by the LSAT) as 'in most cases'. So the conclusion that health stores' salespersons definitely steer their customers towards products from which they derive the highest commission isn't necessarily warranted. A proper conclusion is that they likely do. LSAT logic allows a conclusion that something is likely to happen from premises that indicate that in most cases, something happens. But that realm of logic is used differently from whole to part logic. In your argument, the flaw committed has to do with an inappropriate application of what is known about the majority of salespeople. Even if 99% have the property, you can't say that a given group of salespeople have the property, since the possibility that they are part of the 1% who do not renders that conclusion unsupported.

Hope that's clear. Whole to part flaws and 'most' logic flaws are kind of similar, but mastering them both will enable you to easily distinguish the two on test day.

blackhawksfan

Gotcha! Thanks A LOT again for typing all that out. This is great, learning something new everyday. So generally = usually = cannot apply that property to the group 100% of the time. I have not seen this often on the PTs but if I see it, I will make a note to be careful about distinguishing the flaws. I assume that the answer choice will mirror that language though, by saying that the author cannot presume without justification that what one group generally does together is what each individual group would generally do by him/herself.

Nice reference to the wood-table example! That question really bugged me because all the answer choices seemed the same (It was metal and a desk though).

David Wayne

That's right, you're referring to Preptest 53, Section 3, Question 13, a great question for really understanding when you can and cannot apply whole to part logic (the answer choice with the steel table comprises a logically sound argument, and that's the exact question i was referencing when writing my response).

What they have done, however, on alot of some of the older (and newer) tests is use the word 'likely' to infer an event's likelihood from a most statement. So if they give you A most B, and A occurs, they can conclude B is likely to happen, and that's fine from a logical standpoint. (They often say that B occurs and then conclude that A is likely to happen, obviously an unwarranted conclusion since the arrow and the logic of 'most' is thereby violated).

The 'usually' stuff is used a few times i believe on some of the more recent tests i've done to commit 'most' flaws, so its really important to understand. Glad i could help.