132-3 Microscope Mastery Levels: Applying Mastery Grading to Microscope Skills

Abstract:

Mastery grading is a strategy for providing students with flexible options for demonstrating mastery of learning objectives, and it is particularly useful for assessing skills that are used repeatedly and built gradually.  This presentation describes a novel mastery grading scheme designed for assessing petrographic microscope skills across a 1-semester petrology class, but could be adapted for assessing any set of related skills practiced across multiple classroom or lab activities.  In this example, students learn the fundamentals of microscope operation, identification of common minerals and rock textures, and optical properties used to identify minerals at the beginning of the semester, then practice and apply those skills during lab activities throughout the rest of the semester.  This approach allows students to practice their microscope skills with the goal of achieving mastery by the end of the class.  Students are supplied with a checklist of skills they have the opportunity to master, and are asked to self-assess which skills they have mastered after each lab activity.  As students progress, they track their competency via Mastery Levels, which correlate to the number of skills they have mastered.  The novel mastery grading scheme implemented here replaces lab practical exams with short oral exams wherein students choose the skills on which they will be tested, and the instructor chooses a random subset of the chosen skills to assess.  Students who assess themselves at a higher mastery level have a larger pool of skills on which they could be tested.  The purpose of the oral exam is for the instructor to assess the accuracy of the student’s self-reported Mastery Level, and the instructor can adjust the student’s level based on their performance.  Mastery Levels are directly correlated to a Microscope Mastery Grade, with higher levels associated with higher grades.  A student’s Mastery Level at the end of the semester determines this portion of their overall grade.  Student feedback indicates this mastery grading scheme reduces stress associated with lab assessment (compared to a traditional lab practical exam), improves transparency surrounding learning expectations, and provides students with agency over their own learning.  This grading scheme also provides instructors with a consistent means to track students’ progress throughout the semester and facilitates consistent and constructive feedback for students.  

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