To test his measure, dr. sheffield gives his measure to a group of people in gamblers anonymous (ga) and another group in alcoholics anonymous (aa). he finds that people in the ga group have higher scores on his new measure than people in the aa group. why did dr. sheffield do this?
a. to obtain evidence for criterion validity
b. to obtain evidence for content validity
c. to obtain evidence for face validity
d. to obtain evidence for convergent validity