Figure 3.

Use of mutation in students’ models and short answers on the final exam. (A) Consistency in the use of the mutation concept across two different assessments of the origin of variation, a model and a short-answer (SA) explanation. (B) Distribution of scores attributed to student models and short answers (SA) for their use of the mutation concept. The same rubric was applied to both assessments (Table 1, items 4, 4a, and 4b). (C) A cross-tabulation illustrating how individual student's scores were distributed in the class. Each cell indicates the number of students who had a given combination of scores on their two assessments; individuals on the red diagonal performed consistently across the two assessment questions.