Wright Map Analysis

A Wright map (item-person map) is the signature graphical output of Rasch measurement: it places persons and items on the same vertical scale, with examinee abilities on one side and item difficulties on the other, both in logits. Because a person succeeds on an item with probability one-half when their ability equals the item's difficulty, this shared scaling lets analysts see at a glance how well a test is targeted to its examinees, what the items reveal about the construct's order, and where measurement is sparse. Named for Benjamin Wright and central to Mark Wilson's construct-mapping approach, it is a primary tool for interpreting and validating measures.