Table 3.
Reasoning used by students to determine taxa relatedness from all four assessments
| Group assessmenta | Individual assessment | ||||
|---|---|---|---|---|---|
| Category | Initial homework (n = 24) | Evolution unit exam (n = 23) | Evolution unit exam (n = 88) | Review homework (n = 66) | Final exam (n = 77) |
| Most recent common ancestry | 1 (4) | 17 (74) | 51 (58) | 40 (61) | 54 (70) |
| Monophyletic grouping | 1 (4) | 7 (30) | 19 (22) | 5 (8) | 7 (9) |
| Counting nodes | 6 (25) | 2 (9) | 19 (22) | 12 (18) | 14 (18) |
| Counting synapomorphies | 12 (50) | 6 (26) | 11 (13) | 6 (9) | 2 (3) |
| Branch tip proximity | 5 (21) | 1 (4) | 1 (1) | 1 (2) | 7 (9) |
| Contemporary descent | 0 (0) | 1 (4) | 2 (2) | 1 (2) | 4 (5) |
| External insights | 4 (17) | 0 (0) | 1 (1) | 1 (2) | 3 (4) |
| Negation reasoningb | 0 (0) | 0 (0) | 5 (6) | 3 (5) | 3 (4) |
| Other responses | 1 (4) | 1 (4) | 6 (7) | 9 (14) | 8 (10) |
Values are the number of responses that received a particular code with percentage of responses in parentheses. Note: total number of codes is greater than the total number of responses and the percentages will sum to more than 100% because responses often fell into multiple categories. Italics indicate correct forms of reasoning.
aResponses were submitted by permanent groups of three or four students.
bNegation reasoning is neither correct nor incorrect.