Sun Mi is designing a questionnaire on loneliness. She is concerned that some features of loneliness are similar to depression and to low self-esteem. Which type of validity does she need to show to demonstrate that her questionnaire assesses loneliness and not depression or low self-esteem?

Discriminant validity

Explanation:

Discriminant validity could be explained as proving to show that contents that are not meant to be related are actually unrelated. This helps the audience addressed to know the difference in the information so they don't mix things up and are misinformed. In other for Sun Mi to validate his question considering people may misunderstand it for depression and low self-esteem instead of loneliness, he has to implemet a Discriminant validity in the questionnaire so the audience understand it in the perspective he is looking at.