Tests are often used to make decisions about individuals: an invalid test can lead to deicisions that are both inefective from decision maker"s pov and unfair from the individual"s pov. Correlate test scores with measures of success or outcomes. Predictor (high school grades) vs. criterion (university gpa) will high school grades predict university grades. Concurrent validity both @ same time w/ problems: 1. Assess high school grades via transcript: 2. Correlate the two concurrent validity (look only at those selected into this university, you concurrently look @ hs and university grades) Range of scores in hs grades in this room will not be representative of the entire range in ontario range restriction (you need certain grades to get into university) Predictive validity predictor @ 1 time and criterion @ 2 time: assuring the range of hs grades you get is representative of all of ontario, 1. Assess high school average of every student in ontario: 2.