Chuck Wagon is very excited about the withinsubjects approac

Chuck Wagon is very excited about the within-subjects approach. \"Now I\'ll never need to run large numbers of subjects again,\" he says. However Chuck has forgotten that within-subjects designs may be a) useless, b) impossible, c) confounded by order effects, or d) impractical when excessive subject time spent in an experiment makes data inaccurate. Give an example of each of these four objections.

Solution

Answer to the question)

Suppose we need to find out what affects the IQ of students

for that we have 100 students, asking all 100 student check for each conditon is useless.

it is better to divide the 100 students say in five gorups and then test them under 5 different conditions.

Thus in such a situation the within design seem to be useless

.

When we test a product in different regions and different customer base, the within designs make no sense , because the different regions do not behave same, thus it is impossibe to run the within designs in such scenario. In this scenario we can also observe that their can be confounding variables as well. For example if the product is related to weather changes, that as per the weather of every region the customer behavior would be different.

.