Development of an Evolutionary Tree Concept Inventory

Abstract

Despite the importance of tree-thinking and evolutionary trees to biology, no appropriately developed concept inventory exists to measure student understanding of these important concepts. To address this need, we developed a multiple-choice concept inventory consisting of 24 pairs of items, and we provide evidence to support its use among undergraduate students. A set of learning outcomes was developed to guide the creation of the concept inventory. The learning outcomes, student interviews, and student responses were used to develop and revise inventory items. Supporting evidence was gathered from traditional item analysis, exploratory factor analysis, confirmatory factor analysis, traditional reliability analyses, and comparisons to alternative assessments. Appropriate implementation and utility of the concept inventory are discussed.

Modeling and Measuring Tree-Reading Skills in Undergraduate and Graduate Students

“…A number of instruments have been published that investigate different aspects of tree-thinking (Baum et al, 2005;Naegle, 2009;Halverson, 2011;Halverson et al, 2011;Catley et al, 2012Catley et al, , 2013Gibson and Hoefnagels, 2015;Blacquiere and Hoese, 2016;Leone, 2017;Kummer et al, 2019).…”

“…In their work, they collected data on students' understanding of evolutionary trees through multiple-choice and free-response items, as well as student interviews. Based on these data, they developed learning outcomes that are similar to other published outcomes (Kummer et al, 2019). The resulting 24-item concept inventory has five empirically distinguishable factors with a total of 11 learning outcomes (Table 2).…”

“…Learning outcomes of the ETCI(Kummer et al, 2019) Distinguish between evolutionary trees with differing ordering of the species and evolutionary trees depicting differing evolutionary relationships.3Use an understanding of the theoretical aspects of evolutionary trees to evaluate group and character evolution based on common ancestry and parsimony. A Identify cases of homology and analogy when interpreting an evolutionary tree.…”

Who’s related to whom? Use published phylogenies and make customized tree-thinking assessments

“…Tree-thinking includes a suite of skills and conceptual understanding that enables one to read and interpret evolutionary trees correctly (Baum et al 2005;Thanukos 2009;Halverson 2011;Novick et al 2011;Baum and Smith 2013;Catley 2013, 2016;Kummer et al 2019;Schramm and Schmiemann 2019). College students often struggle when first learning to interpret the information in evolutionary trees (Baum et al 2005;Catley 2006;Meir et al 2007;Gregory 2008;Morabito et al 2010;Halverson 2011;Novick and Catley 2013;Blacquiere and Hoese 2016;Dees et al 2018;Kummer et al 2019). These struggles may continue after initial instruction (Sandvik 2008;Halverson et al 2011;Catley et al 2012;Phillips et al 2012;Dees et al 2014), and impair student understanding of evolution and how it explains both the unity and diversity of life (Starr et al 2012).…”

Seeing the Woods for the Trees Again: Analyzing Evolutionary Diagrams in German and US University-Level Textbooks

“…Bars displayed instead of lines can be interpreted as single, static entities instead of lineages undergoing continuous change. Thereby, learners' misconceptions, such as the idea that evolutionary changes only happen at internal nodes [47], can be reinforced by interchanging lines with bars or boxes.…”