To demonstrate one year of growth, a school can contextualize the average gains made by students over the course of the year relative to NWEA school norms, and summarize that normative growth using the NWEA Conditional Growth Index (CGI) metric. This metric is a standard score (z score or effect size), expressed in standard deviation units, that is calculated by subtracting the growth norm for a group of same-grade students in a school from the average growth attained by those students, and dividing that value by the standard deviation of growth. A CGI of 0.00 or better would reflect one year’s growth in a subject, as the overall average growth of students would meet or exceed the amount of growth generally observed by students in the same grade and subject with the same starting achievement level receiving a similar amount of instructional exposure.

MAP Growth has both student and school growth norms, and the CGI metric is available to contextualize the gains of individual students (student norms) or groups of same-grade students (school norms). The CGI metric for grades-within-schools is included on school and district reports, so there is no need for the metric to be hand calculated. Student-level CGI metrics, which are calculated in generally the same way, are included on classroom and school reports.