After grading 20 very poor term papers,Professor Jones was so upset by his students' writing that he became even more conscious of errors in their papers.Professor Jones' change in his grading criteria is similar to the confound of
A)mortality.
B)history.
C)instrumentation.
D)diffusion of treatment.

Question

Quizplus · Accepted Answer

Instrumentation refers to the possibility that changes in measurement may be responsible for changes in the dependent variable. In this case, Professor Jones' heightened awareness of errors in his students' writing led to a change in his grading criteria, which could have influenced the grades his students received.

After Grading 20 Very Poor Term Papers,Professor Jones Was So