Examining the Role of Major Interim Assessments in Predicting Student Performance Scores and Gains on a State Summative Assessment

To shed light on the predictive value of interim assessments for end-of-year (EOY) state test performance, this paper examines the marginal contribution of three widely used interim assessments – NWEA’s MAP, Curriculum Associates’ i-Ready, and Renaissance’s Star – in forecasting both performance scores and gains on a state summative assessment, conditional on prior state summative test scores. Using data from South Carolina, we find that prior state assessment scores strongly predict EOY summative scores but have limited predictive power for year-to-year summative gains. Adding current-year fall, winter, and spring interim assessments to prior state assessment scores contributes little additional predictive power for EOY summative scores but contributes somewhat more to predicting summative gains. However, gain prediction is constrained by the limited reliability of gain scores. The full set of predictors – three interim assessment administrations plus state test scores from the previous two years – explains only about one-third of the variation in gains.