Chen, Yi-Jui I.Wu, Yi-JhenChen, Yi-HsinIrey, Robin2025-08-282025-08-282024-11-29http://hdl.handle.net/2003/43894A short form of the 60-item computer-based orthographic processing assessment (long-form COPA or COPA-LF) was developed. The COPA-LF consists of five skills, including rapid perception, access, differentiation, correction, and arrangement. Thirty items from the COPA-LF were selected for the short-form COPA (COPA-SF) based on cognitive diagnostic modeling (CDM) analyses. Both parametric and nonparametric CDM and correlational analyses were conducted with the responses of 74 U.S. second-grade students on the COPA-SF. Results supported five skills of orthographic processing represented on the COPA-SF. Concurrent and convergent validity evidence was found for the COPA-SF. Overall, the findings suggest that the COPA-SF is a time-efficient, reliable, multidimensional measure of orthographic processing.enJournal of psychoeducational assessment; 43(3)https://creativecommons.org/licenses/by/4.0/Short formOrthographic processingCognitive diagnostic modelsNonparametric classification method370ResearchArticle