This article presents procedures and results from a 2-year project developing science key vocabulary (KV) short tests suitable for progress monitoring Grade 5 science in Texas public schools using computer-generated, -administered, and -scored assessments. KV items included KV definitions and important usages in a multiple-choice cloze format. A KV and item database was constructed for all Grades 3, 4, and 5 science student outcomes by scrutinizing basal and supplemental instructional materials used in Texas schools. The resulting 620 KV terms and 1,800 test items were formatted for computer administration in computer-generated probes. This study examines results from equivalent KV-science probes, administered to students with special needs on a weekly basis, over 5 or 6 weeks. It also compares results from KV probes versus standard multiple-choice science items in simpler pre-post administration. Results encourage further development of KV-based probes for progress monitoring in the content area of science. (Contains 3 figures.)