The Composite Score is the collective raw scores of multiple subtests transformed by a combination of statistical and psychometric methods designed to maximize predictive validity and provide comparability of scores across seasons. This article provides an overview of what a Composite Score means in FastBridge and where it can be found.
FastBridge uses the following calculations to determine the Composite Score. The first weight uses a vertical scale score to adjust the raw score so that all subtests have equivalent predictive estimates of the underlying skill (i.e., reading and math). The second weight uses a factor loading from a factor analysis for each subtest to estimate growth across screening periods. Thus, the total Composite Score for a screening period combines these weights such that:
Total Composite Score = Raw Scorest1 * (Vertical Scale Score st1) * (Factor Loading st1) +
Raw Score st2 * (Vertical Scale Score st2) * (Factor Loading st2) + … +
Raw Score stn * (Vertical Scale Score stn) * (Factor Loading stn)
Next, the total composite score in each season is transformed to a scale with a mean of 50 and a standard deviation of 15. This linear transformation results in the final composite score.
Final composite score = Total Composite Score * 15/SDsample + [50 - 15/SDsample + Msample]
The combined weights and linear transformation on the raw score provide a more accurate picture for educators to estimate students’ strengths in early reading and math competencies and growth across screening periods. Take a look at Development of earlyReading and earlyMath Composite Score and Explanation of earlyReading and earlyMath Composite Score to learn more.
A Composite Score can be found in the following assessments:
A Composite Score can be found in the following reports: