A DIF analysis compares the performance of two different groups of examinees. The focal group is the one of interest, and it usually represents a minority group such as black students or English language learners. Their performance is compared to a reference group that represents a larger group of examinees such as white students or native English speakers. A population of examinees may contain multiple focal and references groups, but a single DIF analysis involves only one pair of groups (e.g. Asian and white examinees). The analysis is repeated with different pairs of groups to evaluate DIF for a variety of focal and references groups.