A review of the literature pertaining to the effect and influence of commercially-prepared interim assessments in mathematics and language arts literacy reveals a lack of quantitative data to determine the value of these products for school reform. This study examined the ability of commercially-prepared interim pretest and posttest assessments in language arts literacy (LAL) and math to predict student achievement on the state-mandated summative assessment in those subjects. Analyses were conducted using binary logistic regression models. Data for this study included results from the state-mandated grade 8 assessments (NJ ASK 8) for 291 eighth grade students enrolled in two middle level schools located in a suburban/urban central New Jersey community during the 2009-2010 academic school year. The findings suggest that the predictive value of the students' pretest results is very similar to that of the posttest results and call into question the efficacy of implementing both interim pretests and posttests.