The survey design is flawed.?

The survey design is flawed. Is the flaw do to the sampling method or the survey itself?





suppose you are conducting a survey regarding students study habits. form a list of full time registered students you obtain a simple random sample of 90 students. one survey question "how many hours do you study"

The survey design is flawed.?
The method of sampling seems to be OK.


The question is ambiguous. It does not give a time period. Day? Week? Semester? I'd think "Day" is implied, but it should be stated. Also, the average time should should be asked because every day is different.