Answer:
test-taker variables error
Step-by-step explanation:
The students are the test takers and the fact that many of them are not in the best possible health or physical condition can result in a higher percentage of mistakes that are not necessarily related to them not knowing the correct answers, but since they are either so tired or so sick, they might not be thinking clearly or may not be trying hard enough to answer the questions.
This can happen to all of us, if we are really sick, it is very difficult to take a test. Your head hurts and you really are more worried about how bad yo feel than taking the test.