Data Limitations

Due to the adaptive nature of the i-Ready diagnostic reading assessment, a student's score might change slightly from assessment to assessment even without a change in that student's reading ability. The range in which a student's score is likely to vary is known as the Standard Error of Measurement (SEM). On average the SEM for a student's Overall reading scale score ranges from 9.3 to 10.9 scale score points. The SEM for a students subtest scale scores on average range from 18.8 to 36.9 scale score points.

Sample Size

Due to the Standard Error of Measurement associated with the i-Ready's diagnostic reading assessment we must to a certain degree take the scale scores of individual students with a grain of salt. When looking at the i-Ready results of a number of students aggregated together we can have more confidence in results, but we must use caution when looking at the results of only a few students.