Answer:This threat to internal validity is called TESTING.
Step-by-step explanation:
Testing refers a instant when a test is repeated with measures remaining constant as they were in the first test.
If participants are given the same test multiple times it is very likely that they may perform better only because they have mastered the test procedure and can now know how to respond better.
This will affect internal validity of the test because the result are no longer the real presentation of the outcome of the test.
Internal validity refers to how trustworthy an outcome is when looking at the cause and effect.