The Illinois Alternate Assessment (IAA) is the method the state uses to measure the learning of students with the most significant cognitive disabilities. The four performance levels are different than those displayed with the ISAT data. The IAA performance levels are Mastery (blue), Satisfactory (green), Foundational (yellow), and Entry (red).

The use of long term (or longitudinal data) to improve educational decision making is a national priority. This data allows educators and researchers to understand the link between various educational strategies and student performance. Districts generally use longitudinal data as part of school improvement planning. The most common strategies for using data are professional development activities, providing support positions for system implementation, and the development of tools for generating data and tools for acting on the data collected.