The effects of English language proficiency on students' performance on standardized tests of mathematics achievement

With the No Child Left Behind Act (NCLB; Public Law No. 107-110, 115 Stat. 1425, 2002), regular reports of student mathematics achievement are requested, including for the subgroup of students designated as Limited English Proficient (LEP). But, are the test used measuring mathematics ability or language proficiency, and how accurate are the subgroup designations? For LEP students, the accuracy of the progress reports depends on the validity of several assumptions, namely, that the language used on the test is not obscuring evidence of LEP students' content understanding, that LEP students are a homogeneous, clearly defined group, and that LEP students are provided opportunities to learn the critical content tested.;Two related studies explored the validity of these assumptions, with a sample of 916 third-grade students from a California school district. First, the relationship between students' English proficiency and their mathematics performance was looked at in relation to subtests that involved more versus less language. Socio-economic status was also included, in order to see if the effect of language remained beyond what could be explained by SES. Second, additional measures of language fluency were used to determine if district English language proficiency designations could be refined. Third, a subset (n=358) of students received direct instruction in statistics and probability to see whether or not access to the content would help improve student performance, regardless of language proficiency.;Analyses of variance, analyses of covariance, and regression analyses indicated that there is a significant difference in mathematics achievement between LEP and non-LEP students, and that this performance discrepancy decreases as the amount of language in the tests decreases. The use of a simple composite of fluency measures indicated that district English language proficiency designations are vague and can be improved. Direct instruction of students resulted in increased achievement for those who received the intervention, and improved performance of all English language proficiency groups.