The studied high-structure introductory biology course combined four recurring practices: Socratic questioning, at least three ungraded active-learning exercises per class, three to five clicker questions per class, and weekly online practice exams. Students answered clicker questions individually and then reconsidered them after peer discussion. Practice exams gave students 35 minutes to answer five short-answer questions, after which they anonymously graded peers’ responses using sample answers and rubrics. Together, these activities were intended to sustain attention, provide instructor feedback, exercise application and analysis skills, and encourage peer teaching.

High-Structure Introductory Biology Course Design Example

University of Pennsylvania

The authors hypothesized that highly structured course designs, which implement reading quizzes and/or extensive in-class active-learning activities and weekly practice exams, can lower failure rates in an introductory biology course, compared with low-structure course designs that are based on lecturing and a few high-risk assessments. The experimenters controlled for instructor effects by analyzing data from quarters when the same instructor taught the course, exam equivalence with new assessments called the Weighted Bloom’s Index and Predicted Exam Score, and student equivalence using a regression-based Predicted Grade. The authors also tested the hypothesis that points from reading quizzes, clicker questions, and other assignments in highly structured courses inflate. They found no evidence that points from active-learning exercises inflate grades or reduce the impact of exams on final grades. When controlled for variation in student ability, failure rates were lower in a moderately structured course design and were dramatically lower in a highly structured course design. This result supports the hypothesis that active-learning exercises can make students more skilled learners and help bridge the gap between poorly prepared students and their better-prepared peers.

Increased Course Structure Improves Performance in Introductory Biology

To control for exam equivalence and difficulty, the study utilized two primary measurement methods:

* **Weighted Bloom's Index**: Summarizes the average Bloom's level of exam questions weighted by points possible. Levels 1–2 test lower-order cognitive skills, while levels 3–6 assess higher-order skills. Three experienced TAs rated the exams blindly.
* **Predicted Exam Score (PES)**: Establishes grading equivalence. Three experienced TAs (different from the Bloom's raters) predicted the average score for each part of every exam question, while remaining blind to the study's intent.

Increased Course Structure Improves Performance in Introductory Biology: Measurements

There are five main results for the experiments evaluating the impact of increased course structure on performance in introductory biology:
- Exam equivalence
- Exam impact on course grade
- Student equivalence across quarters
- Evaluating the drop rate
- Changes in failure rate in Biology 180

Increased Course Structure Improves Performance in Introductory Biology: Results

Biology 180 was the first course in a three-quarter introductory biology sequence for undergraduates intending to major in biology or related disciplines at the University of Washington. The five-unit course met for four 50-minute class sessions and one two- or three-hour laboratory session each week. The study analyzed six quarters taught solely by S.F., with 400 exam points available each quarter. Most students had completed a chemistry prerequisite and were sophomores. In the most recent analyzed quarter, students were 61.1% female and 38.9% male; 46.7% Caucasian, 38.5% Asian-American, 7.4% from underrepresented minority groups, and 7.4% did not declare an ethnicity. Additionally, 16.4% participated in the UW Educational Opportunity Program. The study reports that these demographics were typical across the quarters and years analyzed.

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