Table 4.

Differences between student and professional grading vary with level on Bloom's taxonomy

	Lower-order cognitive skills	Higher-order cognitive skills	t statistic	p value (two-tailed)
Mean difference: individual students versus professional	0.15 ± 0.02 (688)	0.31 ± 0.02 (1760)	−5.96	<<0.0001

Means are reported with SEs; sample sizes (number of student answers) are in parentheses; the t statistic is from an unpaired test. For a definition of lower-order and higher-order thinking skills, see Methods.