A study is conducted to investigate the effects of a new exercise program on lameness in race horses. A group of horses at a local race track is selected for the study. The horses are randomly assigned to two groups. Group 1 horses will train according to the new program for one month, rest for two weeks, and then train according to the old program for one month. Group 2 horses will have the order of the old and new programs reversed. Here, each horse serves as its own control. The two groups are necessary to avoid:
A)a carryover effect, since the order of treatment may influence the subject's response.
B)a placebo effect.
C)a double-blind effect.
D)a confounded effect.

Question

Quizplus · Accepted Answer

By having two groups with different orders of treatment, the study design allows each horse to serve as its own control and avoids a carryover effect where the order of treatment may influence the subject's response. A placebo effect is not relevant in this study design since the horses are receiving actual treatments. Double-blind effect is also not relevant since it typically involves withholding information from the subjects and/or researchers about the treatment assignment, which is not applicable in this study. Confounded effect is a general term referring to a situation where multiple factors may be affecting the outcome of interest, and it's not clear how it applies specifically to this study design without additional information.

A Study Is Conducted to Investigate the Effects of a New