Benchmark Quizzes in Organic, part 2

[kevin_revell]

Last fall, I implemented a set of benchmark quizzes in my organic chemistry classes.  These quizzes arose from a simple question:  “What should every student who passes my class be able to do?”  Adapting the approach of Joshua Ring, the quizzes were pass-fail, with no partial credit.  Students had more than one attempt to pass the quizzes, but they had to get the quiz completely correct in order to pass.  Further, I tethered the quizzes to students’ homework grades:  In order to receive credit for homework, students had to pass 5 of the 6 benchmarks by the end of the semester.

Not everything went as planned.  My benchmarks were compressed toward the end of the semester, leading me to trim the number of quizzes and removing the restriction on the homework grade.  Nonetheless, the results were remarkable:  Rather than limping through exams with partial credit and moving on to other topics, the multi-attempt, pass-fail approach drove students to analyze their knowledge gaps and hone their understanding.  After two or three failed attempts, students often made their way to my office to figure out what they did wrong.  It clearly made them stronger.

Quantitatively, I was able to compare my class to the previous two semesters, using the ACS standardized exam.  The only major pedagogical change was the introduction of the benchmarks.  Here are the exciting results:

Semester	Students	Average Percentile
Fall 2015	58	56
Spring 2016	40	45
Fall 2017	46	73

I don’t think the Benchmark quizzes can be exclusively credited with these outcomes.  Our fall classes are usually stronger, and this was an exceptional bunch.  However, they definitely contributed.  I was especially interested to see the effect on those students at the bottom of the class, who often have the most pronounced knowledge gaps.  Here is the change limited to those students who finished in the bottom quartile of the class on the ACS exams:

Semester	Students	Average Percentile
Fall 2015	15	17
Spring 2016	10	11
Fall 2017	12	23

This semester, I've moved out of the organic sequence and into Introductory Chemistry.  I'm teaching large daytime and evening sections, and using an adapted benchmark scheme for both.  More to come about this in an upcoming article.