Researcher: Each subject in this experiment owns one car, and was asked to estimate what proportion of all automobil...

BenMingov December 13, 2019

Hi Shafieiava, thanks for the question!

The author hypothesizes that people overestimate the number of cars of the same make as theirs nationally, because in some regions certain cars are more prevalent than others. Presumably, these people are seeing the car of their make more often in their own regions, and therefore overestimating how common the car is on a national level.

The researcher then relies on the study's finding that people do in fact overestimate how common their car is nationally, and uses this to conclude that it is due to the reasoning he provided (i.e. some regions have higher proportion of certain makes).

There is an issue with this though. Just proving that the result you hypothesized is true does not make the reasoning for it true. Simply stating that it is confirmed that people do overestimate how common their car is nationally does not provide the "why".

Answer choice C doesn't address this issue. It fails to see that it doesn't fully matter if the researcher failed to take into account that the people surveyed came from a wide variety of geographical regions. There doesn't necessarily need to be a "wide" variety of regions represented. And additionally, it is implied that he does take into consideration that people come from different regions and this would go against this answer choice.

I hope this helps. Please let me know if you have any other questions.

jingjingxiao11111@gmail.com October 7, 2020

So this question can be thought of as a wronged sufficient necessary logic right? The necessary premise being the result finding that people do overestimate their car model nationwide. The sufficient condition being that certain cars are more prevalent in certain regions than other.
So is it fair to say that just because the necessary condition people do overestimate their car model nationwide turned out to be true does not have to prove the author's reason for it which is a sufficient condition? Thanks