Measuring and Advancing Experimental Design Ability in an Introductory Course without Altering Existing Lab Curriculum

Abstract

Introductory biology courses provide an important opportunity to prepare students for future courses, yet existing cookbook labs, although important in their own way, fail to provide many of the advantages of semester-long research experiences. Engaging, authentic research experiences aid biology students in meeting many learning goals. Therefore, overlaying a research experience onto the existing lab structure allows faculty to overcome barriers involving curricular change. Here we propose a working model for this overlay design in an introductory biology course and detail a means to conduct this lab with minimal increases in student and faculty workloads. Furthermore, we conducted exploratory factor analysis of the Experimental Design Ability Test (EDAT) and uncovered two latent factors which provide valid means to assess this overlay model’s ability to increase advanced experimental design abilities. In a pre-test/post-test design, we demonstrate significant increases in both basic and advanced experimental design abilities in an experimental and comparison group. We measured significantly higher gains in advanced experimental design understanding in students in the experimental group. We believe this overlay model and EDAT factor analysis contribute a novel means to conduct and assess the effectiveness of authentic research experiences in an introductory course without major changes to the course curriculum and with minimal increases in faculty and student workloads.

Laboratory Courses with Guided-Inquiry Modules Improve Scientific Reasoning and Experimental Design Skills for the Least-Prepared Undergraduate Students

“…Gains by students in the lowest quartile were sufficient that differences in posttest scores were no longer significant between students in the lowest quartile and those in the middle two quartiles. However, the posttest scores for students in these three quartiles was similar to the pretest scores for students in the cohorts studied by Sirum and Humburg (2011) and Shanks et al. (2017).…”

“…The categories on the x -axis represent the EDAT scoring rubric items (Table 2) listed in the order of experimental design sophistication (Sirum and Humburg, 2011). Categories in bold font are components of the basic understanding score, and those in capital letters are components of the advanced understanding score based on Shanks et al. (2017).…”

“…Sirum and Humburg (2011) showed that students in laboratory courses in which students had to design their own experiments demonstrated significant increases in experimental design skills, as measured with the EDAT, but that students in traditional laboratory courses exhibited no change. Similarly, Shanks et al. (2017) showed that students in an introductory biology laboratory course that had an authentic research experience integrated into the existing laboratory curriculum exhibited significant gains in experimental design skills (i.e., EDAT score).…”

“…In addition, we maintained consistency in ratings by sitting together during scoring of all responses and discussing those for which there were questions about scoring. Following the analysis of Shanks et al. (2017), we partitioned the first four items, which were deemed lower-level experimental skills (basic understanding), and items 5, 8, and 10, which were deemed higher-level experimental skills (advanced understanding).…”

“…All responses in which students did not answer were removed from analysis. The sum of responses for items 1–10 was the composite score; the sum of responses for items 1–4 was the basic understanding score; and sum of responses for items 5, 8, and 10 was the advanced understanding score, based on Shanks et al. (2017).…”