OG 12 Weaken the argument

[GMATMadeEasy]

Guidebook writer: I have visited hotels throughout the country and have noticed that in those built before 1930 the quality of the original carpentry work is generally superior to that in hotels built afterward. Clearly carpenters working on hotels before 1930 typically worked with more skill, care, and effort than carpenters who have worked on hotels built subsequently.
Which of the following, if true, most seriously weakens the guidebook writer's argument?
(A) The quality of original carpentry in hotels is generally far superior to the quality of original carpentry in other structures, such as houses and stores.
(8) Hotels built since 1930 can generally accommodate more guests than those built before 1930.
(C) The materials available to carpenters working before 1930 were not significantly different in quality from the materials available to carpenters working after 1930.
(D) The better the quality of original carpentry in a building, the less likely that building is to fall into disuse and be demolished.
(E) The average length of apprenticeship for carpenters has declined significantly since 1930.

OA is D

Basically, two data are compared and we are saying that they are not CORRECT representative of skills etc of carpenters because the way data has grown up reflects that data in skewed. OK .

OG explains : If there is some reason to think that hotel with good carpentry survive longer than those with bad carpentry ,then still existing hotels from the old era will have dispropotinotaley more good carpentry, even assuming no difference between the skill, care , and effort of the carpenters from the two eras.

Look at the bold part; basically we are already assuming that old era hotels have good carpentry. How this can weaken the argument ?

I know there is something wrong in my thinking process here.

[M09]

Guidebook writer: I have visited hotels throughout the country and have noticed that in those built before 1930 the quality of the original carpentry work is generally superior to that in hotels built afterward. Clearly carpenters working on hotels before 1930 typically worked with more skill, care, and effort than carpenters who have worked on hotels built subsequently.
Which of the following, if true, most seriously weakens the guidebook writer's argument?
(A) The quality of original carpentry in hotels is generally far superior to the quality of original carpentry in other structures, such as houses and stores.
(8) Hotels built since 1930 can generally accommodate more guests than those built before 1930.
(C) The materials available to carpenters working before 1930 were not significantly different in quality from the materials available to carpenters working after 1930.
(D) The better the quality of original carpentry in a building, the less likely that building is to fall into disuse and be demolished.
(E) The average length of apprenticeship for carpenters has declined significantly since 1930.

OA is D

Basically, two data are compared and we are saying that they are not CORRECT representative of skills etc of carpenters because the way data has grown up reflects that data in skewed. OK .

OG explains : If there is some reason to think that hotel with good carpentry survive longer than those with bad carpentry ,then still existing hotels from the old era will have dispropotinotaley more good carpentry, even assuming no difference between the skill, care , and effort of the carpenters from the two eras.

Look at the bold part; basically we are already assuming that old era hotels have good carpentry. How this can weaken the argument ?

I know there is something wrong in my thinking process here.

Hi GMATMadeEasy,

Let me give it a shot. I could narrow it down to A & D

B - irrelevant; accommodation is not in Q
C - Strengthening by saying that the material was same in both the era
D - irrelevant

Now A & D
A - "The quality of original carpentry in hotels is generally far superior to the quality of original carpentry in other structures, such as houses and stores."
This statement is referring to which era before 1930 or after 1930 we don't know.
I was left with D only, apparently that's the OA.

HTH

[rohu27]

let me tell you the way i interpreted option D (may be wrong, if wrong i will get to knw the flaw, so posting)

conclusion: Clearly carpenters working on hotels before 1930 typically worked with more skill, care, and effort than carpenters who have worked on hotels built subsequently

we need to weaken above.
option D: The better the quality of original carpentry in a building, the less likely that building is to fall into disuse and be demolished
now it may just be the case tht good quality buildings of the past are remaining, and others are demolished. so just by looking at the good quality ones, we cannot comment on the buildings of overal era(that is before 1930's)
it may well be that there may be other buildings which were not built well but we do not know about them as they no longer exist.

hence d weakens

[rohu27]

let me tell you the way i interpreted option D (may be wrong, if wrong i will get to knw the flaw, so posting)

conclusion: Clearly carpenters working on hotels before 1930 typically worked with more skill, care, and effort than carpenters who have worked on hotels built subsequently

we need to weaken above.
option D: The better the quality of original carpentry in a building, the less likely that building is to fall into disuse and be demolished
now it may just be the case tht good quality buildings of the past are remaining, and others are demolished. so just by looking at the good quality ones, we cannot comment on the buildings of overal era(that is before 1930's)
it may well be that there may be other buildings which were not built well but we do not know about them as they no longer exist.

hence d weakens

[fitzgerald23]

1. Hotels built prior to 1930 are superior to those built after
2. Hotel carpenters before 1930 must be better than those after 1930

The question is asking you to weaken the conclusion so we have to find a reason why the carpenters before 1930 may seem better but are not necessarily better.

A. Incorrect. Offers us no information. The comparison the author is making is hotel carpenters pre 1930 and post 1930. Knowing that hotel carpenters were better than other carpenters does nothing to weaken or strengthen the argument

B. Incorrect. Size of the hotel has nothing to do with quality of work

C. Incorrect. This tells us that materials have not changed over time which would actually strengthen the argument.

D. Correct. This tells us that hotels with good carpentry withstand the test of time while those built poorly end up demolished. So this solves the puzzle. Imagine 100 hotels were built prior to 1930. Of those 100 only 10 remain, but they were constructed really well and are of the highest quality. The other 90 may have been horrible. Lets say there are 100 built afterwards that still remain and 5 are of superior quality, 50 are pretty good, 30 are good, and 15 are horrible. In such a scenario the hotels of today are overall better constructed than the pre 1930 hotels with only 15% horrible compared to 90%, but because only the 10 best hotels remain from the pre 1930 it looks as if all hotels from that era were built better, which is clearly not true.

E. Incorrect. Out of scope. Nothing has been noted about how much time a carpenter must train to become a good or bad one.

[nitin9003]

This CR is really confusing and i think all the answer choices are wrong.
If any instructor can explain the answer then it will be very helpful.

[David@VeritasPrep]

received a PM on this one:

Always glad to discuss an official problem! At least we know that there is always a right answer, and just one right answer!

Fitzgerald23 has really nailed the explanation here. This is really good.

Let me address GMATMadeEasy's concern about answer choice D making an assumption.

It might help to look at this as cause and effect. The stimulus is giving us the known effect that in hotels "built before 1930 the quality of the original carpentry work is generally superior to that in hotels built afterward." So this cannot be debated this is a premise and we must accept it.

The cause mentioned in the stimulus is that the carpenters worked with more skill, etc. Basically this is saying that the hotels were built better before 1930.

Now in order to weaken a cause and effect we want to explain the effect in terms of a different cause. Could there be another reason why the person who visited the hotels found that the ones from before 1930 were better? A reason other than the original quality was better?

Yes. there is another possible reason. That reason is time. 1930 was a long time ago. There is no possibility that even half of the hotels from that time have survived to this day. That is mere logic not an assumption. So how does time decide which hotels survive? Why the nicer ones, the ones that are better built are the ones that are kept up and that survive to the present day. So we can explain the CURRENT better quality of the hotels by saying that only the best hotels survived. So as Fitz23 and Rohu27 the majority of hotels before 1930 may have been crap, but that crap did not survive. Maybe only the best hotels did. That would weaken the idea that better initial quality is the reason.

[GMATMadeEasy]

ahh i was missing a point.. what you call a simple logic.. only hotels built before 1930 were demolished not the ones built later. This was the confusion , impeding proper understanding.

I thought any hotel even the new ones without not good carpentry are demolished ..

thanks a lot David and fitzgerald23.

[M09]

Guidebook writer: I have visited hotels throughout the country and have noticed that in those built before 1930 the quality of the original carpentry work is generally superior to that in hotels built afterward. Clearly carpenters working on hotels before 1930 typically worked with more skill, care, and effort than carpenters who have worked on hotels built subsequently.
Which of the following, if true, most seriously weakens the guidebook writer's argument?
(A) The quality of original carpentry in hotels is generally far superior to the quality of original carpentry in other structures, such as houses and stores.
(8) Hotels built since 1930 can generally accommodate more guests than those built before 1930.
(C) The materials available to carpenters working before 1930 were not significantly different in quality from the materials available to carpenters working after 1930.
(D) The better the quality of original carpentry in a building, the less likely that building is to fall into disuse and be demolished.
(E) The average length of apprenticeship for carpenters has declined significantly since 1930.

OA is D

Basically, two data are compared and we are saying that they are not CORRECT representative of skills etc of carpenters because the way data has grown up reflects that data in skewed. OK .

OG explains : If there is some reason to think that hotel with good carpentry survive longer than those with bad carpentry ,then still existing hotels from the old era will have dispropotinotaley more good carpentry, even assuming no difference between the skill, care , and effort of the carpenters from the two eras.

Look at the bold part; basically we are already assuming that old era hotels have good carpentry. How this can weaken the argument ?

I know there is something wrong in my thinking process here.

// some text
B - irrelevant; accommodation is not in Q
C - Strengthening by saying that the material was same in both the era
E(typing mistake earlier) - irrelevant
//some text