Although basing instruction on a learning trajectory (LT) is often recommended, there is little evidence regarding a premise of a LT approach--that to be maximally meaningful, engaging, and effective, instruction is best presented 1 LT level beyond a child's present level of thinking. We evaluated this hypothesis using an empirically validated LT…

The present study tested the "interference hypothesis"-that learning and using more advanced representations and strategies requires the inhibition of prior, less advanced ones. Specifically, it examined the relation between inhibitory control and number line estimation performance. Experiment 1 compared the accuracy of adults' (N = 53)…

Math achievement in elementary school is mediated by performance and growth in number sense during kindergarten. The aim of the present study was to test the effectiveness of a targeted small-group number sense intervention for high-risk kindergartners from low-income communities. Children were randomly assigned to 1 of 3 groups (n = 44 in each…

This report describes a cluster randomized control trial (RCT) intervention study of the effectiveness of the ABRACADABRA (ABRA) Web-based literacy system using a classroom-level RCT intervention with 1,067 children in 74 kindergarten and Grade 1 or Grade 1/2 classrooms across Canada. The authors closely followed the CONSORT criteria for executing…

This study tested the efficacy of supplemental phonics instruction for 84 low-skilled language minority (LM) kindergarteners and 64 non-LM kindergarteners at 10 urban public schools. Paraeducators were trained to provide the 18-week (January-May) intervention. Students performing in the bottom half of their classroom language group (LM and non-LM)…

Using a pretest-posttest comparison-group design, this 16-week study investigated the effects of 2 instructional approaches on the phonological awareness, alphabetic knowledge, and early reading of kindergarten children. The primary goal was to compare a form of contextualized instruction based on an adapted interactive writing program with a…

The purpose of this study was to evaluate the effectiveness of code-oriented supplemental instruction for kindergarten students at risk for reading difficulties. Paraeducators were trained to provide 18 weeks of explicit instruction in phonemic skills and the alphabetic code. Students identified by their teachers meeting study eligibility criteria…