The purpose of the present study was to extend validity research on a content area general outcome measurement tool known as vocabulary matching. Previous research has reported moderately strong to strong correlations between the group-administered vocabulary-matching measure and a standardized assessment instrument. The present study extended the validity research to a statewide accountability assessment. A diverse sample of 146 sixth-grade students from a rural middle school were administered three vocabulary-matching probes and the sixth-grade "i"LEAP ("integrated" Louisiana Educational Achievement Program) social studies criterion-referenced test at different times. Strong correlations were reported between the two measures. Moreover, vocabulary-matching achievement patterns with respect to gender, ethnicity, socioeconomic status, and exceptionality status were similar to those of the "i"LEAP. Alternate-form reliability correlations between the three probes were also strong. Research implications, limitations, and future directions are discussed. (Contains 4 tables.)