Mastery-Based Grading in Chemical Engineering: A Holistic Approach
| Category | Assessment |
| Instructor | Rong Yang, Assistant Professor |
| Department | Smith School of Chemical and Biological Engineering |
| College | Engineering |
| Course Number and Name | CHEME 6400, Polymeric Materials |
| Discipline | Chemical Engineering |
| Course Level | Advanced Undergraduate & Graduate |
| Course Size | 33 students |
| Implemented | Spring 2024 |
“The grading and teaching method really helped facilitate my learning – it encouraged me to always go back to my assignments and think about them once again.” – Student
Brief Summary
Mastery-based grading provides students in an upper-level chemical engineering course with opportunities for iterative learning. Students revise their assignments and exams based on instructor feedback and resubmit with written reflections on their errors and improvements. This approach emphasizes the need for students to demonstrate a deep understanding of core learning objectives.
Learning Outcomes
Research Design Skills
Hypothesis Testing
Analytical Skills
Reflection
Collaboration
Context
After redesigning her Polymeric Materials course with a focus on design manufacturing and making better materials sustainably, Rong Yang wanted to assess her students’ work in a way that fostered creativity, collaboration, and real-world problem-solving. While her students need to know chemical structures, they also need to consider environmental, social, and equity factors. Traditional assessment methods involving problem-solving and calculations were not sufficient for assessing students’ design ability (i.e., formulating a hypothesis, developing a plan, and testing), and they didn’t reflect the realities of work in the field, where there is often more than one correct answer to a problem and the best option is determined through hypothesis testing.
“I feel like in order to assess their design ability…we really couldn’t do it within the frame of traditional grading… That’s where the mastery-based grading comes into play.” – Rong Yang
Implementation
With traditional grading and exams, students often focus on the assessments with the largest impact on their grades. Yang wanted students to care about all aspects of their work and not just high-stakes exams, and so with the help of postdoctoral associate Trevor Franklin, she adopted mastery-based grading, which allowed her to assess her students in a more holistic way. Instead of assigning grades or points to assessments, Yang and her teaching assistants provided broad-level feedback on a student’s demonstrated level of understanding and mastery of core concepts (i.e., well-developed, developing, underdeveloped, or no evidence). In addition, she and her teaching team provided more detailed feedback to help students understand where they could advance their learning. Students had the opportunity to move to a higher level (e.g., from under-developed to developed) by revising their assignments and exams and resubmitting them through the Gradescope tool, including both the new solution and a written reflection on their errors and improvements.
Students were graded on a variety of assignment types (i.e., homework, lab assignments, class participation, teamwork, reflections, prelim, final project presentation, and report), all of which were mapped to the learning goals and the grading scale. At the end of the semester, the student’s mastery level was converted into letter grades, referred to as grade brackets, based on a rubric that outlined the criteria that must be met for the various assessments in that grade bracket. Students’ overall grade for the class thus reflected their level of mastery across all metrics within their grade bracket.
At the end of the semester, students were required to submit a grade reflection where they holistically reviewed their assignments and growth in knowledge, skills, and abilities across the semester. They then requested the grade they believed they had earned based on the criteria for their grade bracket. Students could also include mitigating factors and other exceptional circumstances that may have impacted their grade bracket. Yang reviewed their argument and body of work and, if there were disagreements, she met with the student individually to discuss the grade.
“This course was not only more interesting to me than others, but also more fairly measured my understanding of the material. Assignments were focused on understanding rather than simply getting the correct answer, which helped guide my learning and make sure I actually connected with the material.”
– Student
Challenges
This non-traditional assessment approach required extensive planning and clear communication. Yang offered her students the choice of traditional or mastery-based grading after fully explaining the process, then had them vote on the grading method they preferred. Students overwhelmingly voted for mastery-based grading. While some students initially struggled with the open-ended structure, they adapted well after additional scaffolding and interim feedback sessions.
Reflection and Future Directions
- By taking away the quantitative grade, students focused more on their learning and became more thoughtful with their revision feedback. This also fostered student accountability.
- The reduced grade pressure fostered open discussions around learning objectives and demonstration of learning.
- A great benefit of this method is that it put the students and the teaching staff on the same team. There was less arguing over small points and grades, and the process instead became more collaborative, with the two parties working together towards the final learning goal.
- Both students and teaching assistants preferred this method. Teaching assistants liked that disagreements about point deductions were minimized and that the grading itself was quick for the resubmissions.
- Students demonstrated higher engagement and creativity in the course.
- The alternative mastery-focused assessments improved learning outcomes and student confidence.
- Increasing peer review opportunities could further enhance feedback quality and collaborative learning.
- This method of grading provided a forum for students to consider not only performance, but also evidence for learning outside of graded assessments as different aspects of how grades are determined.
“The mastery-based learning is all about holistic assessment. You need to do well in every metric and these metrics are mapped onto the learning goals.” – Rong Yang
How to Adapt This Approach
- Define clear learning outcomes. Break down the learning outcomes into specific, measurable objectives and keep this list manageable so they can be mapped onto the assessments in the next step.
- Design assessments that target specific learning outcomes. For mastery-based grading to work, the assessment tasks must map directly to learning outcomes. Each assignment, quiz, project, lab, or paper should measure whether students have achieved one or more outcomes. For example, consider using open-ended lab modules to test students’ ability to formulate hypotheses and design experiments to test their hypotheses.
- Simplify the grading scale. A simple scale like “well-developed” (W), “developing” (D), “underdeveloped” (U), and “no evidence” (NE) helps students focus on improving specific areas rather than worrying about precise numerical scores. These should be provided with detailed, actionable feedback to help students understand where they stand and how to improve. While this sounds time-consuming, teaching assistants report that it takes less time overall compared to traditional grading because it incurs fewer arguments over point deductions.
- Offer students multiple opportunities to demonstrate mastery (reassessments). A key tenet of mastery-based grading is allowing students to revise work or reassess, prioritizing learning over penalties for initial mistakes. Set guidelines for reassessments to manage workload, such as limiting reassessment to once, focusing only on the modifications, and coordinating deadlines for the submission of reassessment with consideration of other assessment submissions.