Tara wanted to assess the reliability of her measure of happiness, so she had a group of introductory psychology students complete the measure of happiness two times and then compared the scores, calculating a correlation coefficient. What method did Tara use to assess reliability?

Answer: Test-retest reliability

Explanation:

Test-Retest reliability is defined as the method in which test is performed with same condition and factors for same measure in successive order so that closeness and reliability of the test results can be determined over the time. It is also known as retest reliability.

As per the mentioned situation, Tara is using he test-retest reliability asses for happiness testing. She is testing the happiness measure two times with the same group of people in same condition for gaining the outcomes to compare.