Answer:Practice effects
Step-by-step explanation:
Practice effects occurs when we take the test more than one time and the test result are influenced by the fact that we have had the time to practice more or we are more familiar with the questions. Having more time to practice will enhance our performance and increase the scores that we obtain.
This may be a problem if for example a researcher is measuring a particular traits in students because the more they practice that will have an impact on the overall test if it is repeated and it won't be a true representation of how an individual will perfom normally.