Researchers, educators and psychometricians working with the Northwest Evaluation Association developed the Measures of Academic Progress, a longitudinal study which is used to measure and compare student skills and growth changes over a set period of time. The MAP tests are computerized adaptive assessments that respond to a student’s answers as the test is taken and adjust the level of difficulty up or down as needed.
Immediate Grading on the MAP
Students who answer correctly are given increasingly more difficult questions until they answer one incorrectly. Students who have incorrect answers are given easier questions until they answer one correctly. Then the difficulty increases again. Ideally, a student will score approximately half the questions correctly and half the questions incorrectly. After a student takes the exam, the RIT scale score is reported immediately.
Rasch Unit for Scoring
Named for a scoring scale construction model called the Rasch Unit, invented by Danish mathematician, Georg Rasch, “the RIT Scale is a curriculum scale that uses individual item difficulty values to estimate student achievement,” according to the NWEA. Each test item on the assessment corresponds to a value on the RIT Scale. The scale assigns a value of difficulty to each item, so the difference between scores is the same regardless of whether a student is at the top, bottom or middle of the scale. The NWEA also says that in scoring the exam, growth targets are developed “to describe typical or anticipated growth over a period of time from the normative data.” As a student takes the exam over a period of set intervals, usually two to three times a year, his academic growth is determined by how he meets his growth targets.
The RIT Scale
The RIT Scale ranges from 150 to 300. Students in the third grade typically score from 150 to 190 and progress to 240 to 300 when they are in high school. The numbers of the scale relate directly to difficulty of the items on the test. To fully demonstrate how this scale works, RIT chart maps, available on the NWEA website, were developed to illustrate the exact type of questions answered to achieve a score in a specific category.
Standardized Test Correlations
Although the MAP is not designed to be a test of college readiness, it is very accurate in predicting how well a student will do on a standardized exam. In a correlation study completed in 2012, the scale scores of the MAP were compared to the standardized scores of the ACT Testing Program: EXPLORE, PLAN and ACT. The study determined that a student’s MAP score was predictive with a 75 percent to 90 percent accuracy in determining his score on college readiness exams. The NWEA also reports that many universities use the MAP because it can accurately measure and compare "growth among students from differing schools, districts and states."