The course and malleability of reading achievement in elementary school: The application of growth curve modeling in the evaluation of a mastery learning intervention

In a defined cohort of 363 Baltimore children, the growth of reading achiev ement over elementary school was found a non-linear, cubic function. Subseq uently, a Mastery Learning (ML) intervention designed to improve reading ac ievement was evaluated. Over first grade, a significant positive interventi on effect was found with considerably more children in the ML condition mak ing the expected achievement gain. However, the Growth Curve Model (GCM) of reading achievement for ML in later elementary school had a flatter slope than GCM for control children. This result was likely due to the finding th at the GCM for those in the ML condition who failed to respond to the inter vention in the short-term had a comparatively poorer outcome than the remai ning children in both the Mi. and control conditions. Results are discussed within the framework of "Matthew-effects" which result in rich-get-richer and poor-get-poorer patterns of reading achievement.