The purpose of this study was to field test a two-tiered instrument including multiple-choice and short answer tasks to assess college students’ ideas and level of understanding in genetics. The instrument was constructed from previously tested assessment tasks and findings from the current research literature. Ninety-seven freshmen enrolled in a biology lab course were surveyed. Test validity and reliability were measured using Chronbach coefficients. Multiple-choice and short answer responses were analyzed using descriptive statistics to identify frequencies of answer selections. Written responses were independently evaluated using a five-point scoring rubric by three researchers to identify common misconceptions revealed in students’ written responses. A purposeful stratified sample of 15 students was selected across low, middle, and high performance on the instrument for individual interviews.
Findings revealed that undergraduates have a variety of ideas concerning gene concepts. While the instrument revealed student conceptual difficulties, there also were issues with previously tested survey items. The findings suggest students possess superficial understanding regarding transcription and translation. Students also hold hybrid conceptual models of gene structure and function. The paper presents a critique of the instrument and discusses the broader impacts to teaching and learning college biology. Recommendations for improving assessment techniques also are discussed.