"Parse Tree" <parsetree at hotmail.com> wrote in message
news:EYe%8.9721$sb5.694385 at news20.bellglobal.com...
> "John Knight" <johnknight at usa.com> wrote in message
> news:Ce7%8.15841$Fq6.1704086 at news2.west.cox.net...> >
> > If the test designers equally distributed the correct answers over A.,
B.,
> > C., and D. (which they did), then the correct answer will be selected
25%
> of
> > the time (if all students just guessed at random).
>> Random guesses are independent of what the actual answer is. That's why
> thy're called 'guesses'.
>>>
This is true. The argument had been made that a non-even distribution of
how the correct answers were assigned to different letters, A), B), C), and
D) would bias the results, but the reality is that a random selection
cancels this out as a possible factor.
Also, the 3% standard error is too big for this distribution. Where 25% of
the students answered A) by chance, the standard error is closer to 25% x 3%
= .75%, rather than 3%.
