Facilitating the development of reasoning skills in undergraduate ecology classes

Background/Question/Methods

Colleges and universities are being urged to improve the teaching of reasoning skills, by medical schools (HHMI-AAMC), scientific organizations (e.g. AAAS) and employers. Students who major in the biological sciences develop reasoning skills at a lesser rate than comparable students who major in mathematics or the physical sciences, students from groups under-represented in science develop these skills at a lesser rate than comparable students from the majority, and current students are developing these skills at a lower rate than students did in the 1980s.  Thus there is an urgent and widely acknowledged need for the development and adoption of more effective methods for teaching reasoning skills to biology undergraduates. Cognitive science research indicates that advanced reasoning skills are domain-specific and therefore best taught to these students within their biology classes, so for this initial stage, the focus was on mathematical problem solving, use of graphical representation, and heuristics and biases in reasoning in an undergraduate Ecology class. The objective of this first stage was to investigate the suitability and effectiveness of a variety of topics, modes and delivery formats, by developing instructional materials, using them, and evaluating with learning gains (pre- and post-test) and student evaluation.

Results/Conclusions

Materials developed for the teaching of quantitative problem-solving and graphical representation included lecture slides, problems for in-class discussion groups and homework problems, on the topics of population genetics, population growth models, food webs and biogeochemical cycle diagrams. For these topics, the materials were effective as indicated by student learning gains, pre- and post-test, and positive student evaluations, with average ratings of ‘very helpful’ on a 5-point Likert scale for lecture and ‘helpful’ for in-class discussion and homework problems. Materials developed for the teaching of the role of heuristics and biases in scientific reasoning included interactive classroom demonstrations. For example, in demonstration of anchoring and adjustment, half of the class was presented with a high anchoring value (“Is the average temperature of Minneapolis above or below 100ᵅF?”) and half presented with a low value (“…0ᵅF?”), and then all were asked to make their best guess of the actual average annual temperature. The average temperature estimated by the high-anchor group was significantly higher (avg. 65ᵅF vs. 45ᵅF; p=0.001).  Students judged this demonstration very effective. Overall, student evaluations rated these activities ‘very helpful’ in teaching reasoning skill; although establishing strong connection to course content was often noted as an important design characteristic.