Dr Slabbert plans on introducing a new exam review procedure in his chemistry classes. To check the effectiveness of the new procedure he is going to have half his students try the new technique for one semester, while the remaining students review in the way they have always done in the past. He asks each student to decide which of the techniques they would like to use, the new technique or the standard technique. In this example, Dr Slabbert's procedure illustrates

Question

Quizplus · Accepted Answer

Dr Slabbert is not randomly assigning students to the new or standard technique groups, but rather allowing them to choose which group they want to be in. This introduces the possibility of selection bias and therefore the use of non-random assignment.

Dr Slabbert Plans on Introducing a New Exam Review Procedure