(588f) Alternate Models to TA-Graded Homework

The graduate curriculum at Oklahoma State University requires graduates students to take two core courses each semester during their first year.  The number of students enrolled in the courses can vary from as few as 10 to as many as 25 students.  During semesters when enrollment is low, the number of students is too few to warrant a dedicated teaching assistant to grade homework but high enough to require significant time from the instructor.  As a possible solution, we investigated two alternative models for grading homework, self-assessment and peer-assessment, and compared the results to the traditional approach of having a teaching assistant evaluate the homework.  The same group of graduate students was used to investigate both models in two different core courses: i) Selected Diffusional Unit Operations and ii) Advanced Chemical Reaction Engineering.  Using the self-assessment model, students’ homework were collected, copied, and returned to the students to grade and report their scores. Using the peer-assessment model, students’ homework were collected and redistributed to randomly selected classmates who graded the homework and reported the scores.

One obvious concern is grade inflation due to students who grade homework more generously than a teaching assistant.  For one of the two courses where an alternative model was used, we can directly compare homework scores reported by a teaching assistant from previous semesters to homework scores reported from peer-assessment, and there does appear to be some minor overall grade inflation.  This effect can be overcome, however, by adjusting the weighting of the homework in the overall course grade and taken alone should not be a reason to avoid one of the alternative methods.  In fact, based on survey results at the completion of the courses, most of the students reported greater learning from the alternative models that required them to grade either their own or a peer’s homework.  Comparing the two alternative methods, students who graded their own homework expressed a higher level of satisfaction and confidence in the grading than students whose homework was graded by a peer.