Calculating Diversity Index

What is Diversity Index?

Diversity Index (DI) captures the racial and ethnic diversity of our student body with a single number. The DI expresses the probability that any two students chosen at random will have different racial or ethnic backgrounds.

Example of DI

DI is calculated using the following formula:

Pr(same race) = Pr(Caucasian)2 + Pr(African American)2 + Pr(Native American)2 +
Pr(Asian American/Pacific Islander)2 + Pr(Hispanic)2 + Pr(Multi)2 + Pr(IntNatl)2 +
Pr(Unknown)2

In a sample university with a population of 9,961, the probability of randomly picking two students with the same racial identity is about 67 percent or nearly 7 out of 10:

Pr(same race) = Pr8117(0.815)2 + Pr1000(0.100)2 + Pr23(0.002)2 + Pr85(0.009)2 +
Pr124(0.012)2 + Pr49(0.005)2 + Pr453(0.045)2 + Pr110(0.011)2

Pr(same race) = .66+.01+.00+.00+.00+.00+.00+.00 or .67

The probability of picking two students with different racial identities is about 33 percent or 3 out of 10:

Pr(different race) = 1-Pr(same race)

Pr(different race) = 1-0.67 or 0.33