Explanations and Implications of Diminishing Intervention Impacts Across Time

Abstract

Abstract Early academic interventions that boost children s school readiness often show smaller or no discernible differences between treatment and control children in the years following the end of treatment. This pattern of declining impacts has important implications for theories of children s mathematical development. In particular, patterns of fadeout can be used to estimate the relative sizes of the effects of prior knowledge and other factors in producing differential stability in children s mathematics achievement across development. Further, the pervasiveness of fadeout implies the need to reconsider research design and statistical analysis in research on children s mathematical cognition. Especially needed are long follow-up assessment intervals in some experimental research and comparisons of estimates from nonexperimental longitudinal research on mathematical cognition with experimental impacts. Finally, fadeout deserves careful consideration by those attempting to translate research on mathematical cognition into interventions intended to produce positive effects on children s long-term mathematics achievement.