GMATGuruNY wrote:

sui generis wrote:Below are two official questions of which the first one is an official correct answer whereas the second one has problem with while. The official explanation for the 'while' problem states while wiling creates an incomplete construction.

Industrialization and modern methods of insect control have improved the standard of living around the globe while at the same time introducing some 100,000 dangerous chemical pollutants that have gone virtually unregulated since they were developed more than 50 years ago.

Many people have a disinclination to recognize the weakness of their analytical skills while willing to admit their lack of computer skills or other technical skills.

Could someone please explain why the usage of while is correct in first sentence and wrong in the second one.

Industrialization and modern methods have improved...while INTRODUCING.
Here, introducing is a VERBing that implies ACTION.
The construction here is while + VERBing.
The purpose of this construction is to indicate that one action (have improved) is performed in the course of performing another action (introducing).

Many people have a disinclination to recognize...while WILLING.
Here, willing is not a VERBing but a basic ADJECTIVE.
To be WILLING means to be INCLINED to do something.
Since willing conveys not an action but a QUALITY, the construction here makes no sense.

vk_vinayak wrote: Mitch,

'while' can used to mean either 'simultaneously' or 'whereas'. Here in the correct answer (the 1st one) we already have 'at the same time', so I am assuming that 'while' is used to mean 'whereas'. If that is the case, shouldn't it be followed by a clause?

Eg: Minivans carry seven passengers whereas minibuses can accommodate up to 15 passengers.
Minivans carry seven passengers while minibuses can accommodate up to 15 passengers.

GMATGuruNY wrote:

sui generis wrote:Below are two official questions of which the first one is an official correct answer whereas the second one has problem with while. The official explanation for the 'while' problem states while wiling creates an incomplete construction.

Industrialization and modern methods of insect control have improved the standard of living around the globe while at the same time introducing some 100,000 dangerous chemical pollutants that have gone virtually unregulated since they were developed more than 50 years ago.

Many people have a disinclination to recognize the weakness of their analytical skills while willing to admit their lack of computer skills or other technical skills.

Could someone please explain why the usage of while is correct in first sentence and wrong in the second one.

NO COMMA + WHILE + VERBing serves to express an action happening AT THE SAME TIME as a preceding action.
It cannot serve simply to indicate a CONTRAST.

Industrialization and modern methods HAVE IMPROVED the standard of living...while at the same time INTRODUCING dangerous pollutants.
Here, while serves to indicate that one action (introducing) is happening AT THE SAME TIME as a preceding action (have improved).
Please note that GMAC does NOT consider while at the same time an error of redundancy.
Here, at the same time serves a rhetorical purpose: to emphasize that industrialization and modern methods provide benefits and cause problems AT THE SAME TIME.

Many people HAVE A DISINCLINATION to recognize...while WILLING to admit their lack of computer skills.
Here, there are NOT two actions happening at the same time.
Rather, while serves to indicate a CONTRAST.
Thus, the use of NO COMMA + WHILE + VERBing is not appropriate.