Reliability and validity are integral concepts in assessment design. Test speededness, the influence of time constraints on test-taker performance, is an often overlooked threat to both reliability and validity, especially in classroom-based testing. This study evaluates the degree of test speededness of classroom-based assessments that have been developed and tested for a curricular reading intervention study with third grade gifted students. The results of the study inform researchers about whether the validity and reliability estimates for classroom assessments are sound and therefore whether the subsequent analyses from the assessments are reasonable.