Determining Real Learning Gains: Measuring retention of factual, procedural and conceptual knowledge after a first year biology class

At our institution, the use of (validated) pre- and post-tests to assess the effectiveness of teaching and learning activities is becoming increasingly common in Biology as well as in some of the physical science (e.g. Physics, Earth and Ocean Sciences). Students typically complete the pre-test at the start of the course (or prior to being exposed to the tested material) and an identical post-test at the very end, before the start of final examinations. The pre-/post-tests usually comprise validated concept inventory questions as well as some in-house questions. While the data obtained by comparing pre- to post-test scores only inform us about student learning that occurred during the course, as instructors we are usually interested in implementing practices that support longer term knowledge retention. To investigate knowledge retention among students in a large, First Year, Biology course we recruited over 100 students three months after they completed the course final examination, and invited them to write the pre-/post-test for a third time and/or to re-write a subset of questions from their final examination. Ninety-eight students from three different course sections (two “active”, one more “traditional”) completed all of the pre-, post-, and retention tests, and over sixty re-wrote part of their final examination. We will discuss changes in student performance between (pre-), post- and retention testing, and highlight differences in patterns in relation to test item topics, type of knowledge necessary to successfully answer the question (factual, conceptual, procedural) and teaching strategies that students were exposed to (“active” vs. “traditional”). Similarities and differences between our findings and other knowledge retention studies outside of Biology will also be discussed