Imagining, designing, and interpreting experiments: Using quantitative assessment to improve instruction in...

Area of Science:

• Biology Education
• Scientific Reasoning Assessment
• Cellular and Molecular Biology

Background:

• Effective science education requires understanding student challenges in developing scientific reasoning skills.
• Undergraduate students often struggle with core scientific reasoning competencies such as hypothesis formation, experimental design, and data interpretation.
• Identifying specific reasoning errors is crucial for improving pedagogical approaches.

Purpose of the Study:

• To design and validate an assessment tool measuring undergraduate scientific reasoning in cellular and molecular biology.
• To identify common errors in hypothesis formation, experimental design, and data interpretation.
• To evaluate the effectiveness of the assessment in tracking improvements in scientific reasoning across different instructional levels.

Main Methods:

• Development of an assessment with intermediate-constraint, free-response questions and a defined rubric.
• Application of the assessment to undergraduate students in a senior-level biochemistry laboratory course and a first-year introductory biology lab course.
• Statistical analysis to measure improvements in scientific reasoning and identify common errors.

Main Results:

• The assessment demonstrated statistically significant improvements in scientific reasoning among senior-level biochemistry students.
• A greater improvement was observed in biochemistry lab students compared to first-year introductory biology students.
• Common errors included hypotheses restating observations and inappropriate comparisons to absent experimental controls, particularly among introductory students.

Conclusions:

• The developed assessment is a valuable tool for measuring scientific reasoning improvement in undergraduate biology.
• Targeting specific errors, such as hypothesis formulation and the use of experimental controls, can enhance science instruction.
• Difficulties with experimental controls appear widespread among undergraduate students, necessitating further pedagogical focus.