Have you ever taken these sorts of tests? They are not fun. Many questions are childish. Others make you feel stupid for not getting them right. Both extremes are necessary to the study.
So you're saying it's logical that a lot of people dropped out? Seems reasonable.
But that doesn't mean that you wouldn't have the problem of the high drop-out rate implying the final people remaining are biased sample. When you are filtering a large number of people down to a small number, making sure that small number is representative of the large number is a hard problem.
Maybe there's no solution or no easy solution. Doesn't change the problem.
So you're saying it's logical that a lot of people dropped out? Seems reasonable.
But that doesn't mean that you wouldn't have the problem of the high drop-out rate implying the final people remaining are biased sample. When you are filtering a large number of people down to a small number, making sure that small number is representative of the large number is a hard problem.
Maybe there's no solution or no easy solution. Doesn't change the problem.