# Publications & Resources

# Dimensionality of NAEP Subscale Scores in Mathematics

#### Aug 1997

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Jamal Abedi *

In this analysis of 1990 and 1992 NAEP mathematics scores,’ CRESST/UCLA researcher Jamal Abedi examined whether the five subscales (numbers and operations; measurement; geometry; data analysis, statistics, and probability; algebra and functions) of the NAEP mathematics assessment measure (a) a single, broad mathematics skill factor only, (b) five distinct student skill factors, or (c) both a single, broad mathematics factor and five distinct student skill factors. The findings showed that the NAEP mathematics test, for the general student population, measures a single, overall mathematics skill. These results were consistent across three separate grade levels for both the 1990 and 1992 NAEP scores. However, Abedi found evidence of multidimensional scores when background and instructional variables were included in the study, such as students’ own feelings of mathematics competence or how often students reported that they worked with manipulatives in their classrooms. “The findings,” concluded Abedi,”suggest that the single, broad math factor model for reporting NAEP scores fails to include important information available from the students’ background variables.”

Abedi, J. (1997). *Dimensionality of NAEP subscale scores in mathematics* (CSE Report 428). Los Angeles: University of California, Los Angeles, National Center for Research on Evaluation, Standards, and Student Testing (CRESST).