Flipping the Classroom

This semester I am experimenting with a “flipped” classroom for my undergraduate course in deterministic operations research, INSY 3410.  Although it’s still too early to know if this experiment was a success, I wanted to share some of my observations at the mid-way point (and to include some student comments for good measure).

Background:  This course covers the foundational deterministic OR topics of linear programming (e.g., modeling LPs, solving via the simplex method, solving via Excel Solver and Gurobi, and basic sensitivity analysis) and network problems (e.g., shortest path, minimum spanning trees, transportation problems, and assignment problems).  Traditionally this course featured 50-minute lectures on MWF.

Motivating Factors for Flipping:  The most common comment made by students in end-of-semester course evaluations is that they would “like to see more example problems.”  The traditional lecture-based teaching model made it difficult to dedicate sufficient time to both introducing the concepts and working practice problems.

So, this semester I recorded “short” (5- to 30-minute) lecture videos on the key course topics.  These videos take the form of screencasts, where I talk over a set of slides.  I make the slides available to the students so they can annotate them while watching the videos.  [I’ll post all of these materials to this Website soon.]

Before class, the students are expected to (1) read the sections of the textbook related to each video, and (2) watch the assigned video(s).  The goal is for students to come to class prepared to investigate these topics in greater detail (having gained a basic understanding through the videos and textbook reading).  In particular, classroom time is now dedicated to working practice problems that help students better understand the topics and allow us to have more meaningful discussions.  I post the in-class exercises to the course Website before class; during class I ask the students to form small groups (2-4 students) to solve the problems.  If the students encounter difficulties we stop and have a class discussion.

Of course this model requires students to read and watch videos before class, which can be time-consuming.  To compensate for the extra outside-of-class time requirements, I have made the Friday classes optional.  However, rather than canceling the Friday time slot, the teaching assistants work more practice problems and provide general guidance on homework assignments.

Preliminary Observations:  As an instructor, I find this model to be much more enjoyable.  Those students that come to class prepared are more engaged and ask interesting questions.  It is rewarding to watch students collaborate to solve problems.  Although it has been time-consuming to write/record the videos, I believe this was a worthwhile investment.

From the students’ perspective, the results have been mixed.   Based on the student responses to a mid-term course evaluation, many indicated that they prefer to watch the “lecture videos” on their own and work problems in class.  However, judging by the statistics on video views, a disturbingly small percentage of the students actually come to class prepared.  For example, of the 103 students enrolled, only 63 had watched the video on the simplex method before class.   Not surprisingly, when I asked the students to solve problems in class, many were unable to do so.  I suspect that these were the students who indicated that they do not like the flipped classroom.


Cumulative number of students who had watched the “simplex algorithm” video before the Sept. 3 lecture.

(Some) Lessons Learned: I believe that there is value in this approach to teaching this course.  However, there are a few things that I’d like to do differently.  First, the videos need to be (at least somewhat) entertaining.  Second, many students need to be motivated to watch the videos before class; “watch the videos for the sake of learning” is not sufficient.  One option is to conduct a short quiz at the beginning of class that covers the key topics of the videos.  Another option is to grade the in-class assignments.  Currently, these assignments are not a component of the students’ overall grade.  Finally, to accommodate the students’ unique learning styles, I believe it’s a good idea to maintain a mix of traditional lectures with video-based lectures.

I’m curious to hear from those of you who have tried new teaching strategies.