Pre- and post-tests from two of the implementations have been scored. Implementation M1 involved two teachers and four classes in a suburban school using an early version of BioLogica. Implementation L1 involved only one teacher and four classes in an urban school and the latest version of BioLogica. Both implementations involved college-bound as well as non-college-bound classes and each class was matched to a control class, taught by the same teacher, that did not use BioLogica.
A comparison of overall scores on the pre- and post-tests, aggregating the college-bound and business classes, indicates that in the M1 implementation BioLogica students achieved the same learning gains as control students, whereas in the L1 implementation the BioLogica students had significantly higher gains. Those gains were mainly attributable to the model-based reasoning portion of the test: specifically, the cause-to-effect items. The main difference between the two implementations was a significant change in the nature of the BioLogica activities: in the L1 implementation some scripts had been modified to include advance organizer questions, metacognitive prompts, and open-ended summary questions.