If you've heard of NWEA, then you probably know about their MAP (Measures of Academic Progress) Tests. These computer based tests provide teachers with a more in depth look at how the student is doing, as well as showing how they are progressing if they've taken the test before.
The computerization of the test allows for the test to be adaptive. This means the questions get harder if the student answers correctly until they begin giving incorrect answers. Conversely, if a student is giving incorrect answers, the test questions become easier until the student begins answering them correctly. This means a more accurate result on the test, plus the test will be unique to each student based upon their individual abilities and knowledge.