Evaluating Difficult Plant Science Concepts in an Introductory Horticulture Course Using Conceptual Maps as Assessment Tools

Large, introductory horticulture courses are often populated with non-science majors that are taking those courses to fulfill science requirements. These students can struggle with difficult, complex plant science concepts; common examples include photosynthesis and respiration. Previous research has shown that one of the key issues with these misconceptions is that students grapple with comprehension of the relationship between photosynthesis and respiration in plants.  Conceptual maps are a teaching tool that illustrate the relationship between concepts, and can be also used to detect common misconceptions retained by students. Therefore concept maps have the potential to not only help detect commonly held misconceptions, but can also help provide scaffolding that can address and remediate mistaken understandings.  Utilizing a constructivist approach, a semi-structured conceptual map was developed as an assessment tool to detect commonly held misconceptions about photosynthesis and respiration in an introductory horticulture course at a U.S. Land Grant University. Results indicate that students' misconceptions associated with photosynthesis and respiration in that course are: (1) photosynthesis gives energy; (2) plants use CO2 during respiration; (3) respiration reaction is opposite to photosynthesis; (4) respiration happens in the dark and photosynthesis in the light; (5) the goal of photosynthesis and respiration is produced energy to keep the plant alive.