A Validation Study of Standardized Elementary Science Test Scores

The Indiana Statewide Testing for Educational Progress-Plus (ISTEP+) was designed to assess student mastery of key educational goals. The 5th grade ISTEP+ Science Test (5-GIST) is part of the ISTEP+ testing regime. Since its inception, the purpose of the tests has shifted from assessment of individual student academic progress to evaluation of the quality of the educational institution administering the tests. The validity of this use has never been established. This study assesses the validity of the 5-GIST as an instrument for assessing and forming judgments about the quality of science instruction in a particular school. ISTEP+ scores of 2 cohorts of students in a Midwestern school district were converted into Z-scores and tracked from 3rd to 5th grade. A regression line was established to account for the general aptitude and the socio-economic status (SES) of the students. The residuals of the 5-GIST scores revealed that between 57% and 60% of the variance in the scores can be attributed to the general aptitude and SES of the students. Thus, the quality of teaching can have, at best, a secondary impact on the test scores.