In a study of human development, investigators showed two movies that were different types to groups of children. Crackers were available in a bowl, and the investigators compared the number of crackers eaten by children watching both movies. One movie was shown at 8 AM (right after the children had breakfast) and the other at 11 AM (right before the children had lunch). It was found that during the movie shown at 11 AM, more crackers were eaten than during the movie shown at 8 AM. The investigators concluded that the different types of movies had different effects on appetite.

Question

konradzuse · Answer

The results cannot be trusted because
A.	the study was not double-blind. Neither the investigators nor the children should have been aware of which movie was being shown.
B.	the investigators were biased. They knew beforehand what the study would show.
C.	the investigators should have used several bowls, with crackers randomly placed in each.
D.	the time each movie was shown is a confounding variable.

konradzuse · Answer

I'm not sure if A makes sense...  B I don't think is true, I don't think C would have only changed cracker amountrs slightly, because of reachability which is dumb...  and I'm not 100% sure on thre definition of D... :(

konradzuse · Answer

@jim_thompson5910

konradzuse · Answer

@JakeV8

anonymous · Answer

D.

The natural daytime variation in hunger levels (after breakfast vs. before lunch) confounded the attempts to measure the effect of the movie type on snack consumption level.

konradzuse · Answer

Damn Confounded! :)

anonymous · Answer

C could be true, but it isn't the primary effect going on... D is correct, confoundit!!

konradzuse · Answer

Thanks!