Jason is interested in the topic of perception. He has participants complete a task on a computer and measures reaction and number of errors. Jason is thinking of repeating this task after the participants have been exposed to the independent variable. Which of the following reasons bests describes why Jason might not want to have participants complete the task again? a. ethical concerns
b. more statistical variance
c. practice effects
d. none of the above

Practice Effect is a term often used in psychology, it describes the a situation whereby the an individual or participants in an experiment, get to improve his or performance in the test taken during experimentation, as a result of taking the same test more than once.

Hence, in this case, the correct answer is PRACTICE EFFECT, because with practice effect, the number of errors that will be recorded from each participant will reduced over the course of repeating the test.

Option A is wrong, because the test has nothing to do with ethical concerns.

Option C is wrong because the purpose has nothing to do with how far their scores are spread out from their average value.

Option D is wrong either, because the correct answer is option B.