Iterative design of a simulation-based module for teaching evolution by natural selection

Table 3 Study 1—Summary of hierarchical linear model results of pre and post-test data

Q: Do students show improvement on assessment after using the tutorial version of the module? A: Yes. Students had a mean gain of 12.11 points after using the tutorial version of the module
Score ~ time
Fixed predictor	Estimate ± SE	p value
Intercept	64.01 ± 2.55	< 0.0001
Time	12.11 ± 0.41	< 0.0001

Q: Do advanced students perform better than beginner students on the assessment? A: No. Advanced students did not perform better than beginner students
Score ~ time + type + time * type
Fixed predictor	Estimate ± SE	p-value
Intercept	62.25 ± 3.42	< 0.0001
Time	12.30 ± 0.50	< 0.0001
Type of class	4.25 ± 5.33	0.445
Time * type of class	− 0.61 ± 0.89	0.496

Both models include random factors for student (level 2) and class (level 3) to account for the lack of independence between scores. Full model taxonomy included in Additional file 1: Table S6; means for beginning and advanced classes shown in Additional file 1: Table S7 (2644 observations on 1322 students within 13 classes)