Not Lecturing In a Material and Energy Balances Course

We have replaced 50 minutes of lecturing in our material and energy balances course with a more active learning approach that takes advantage of research in learning^1-5 and readily-available technology. Instead of a 50-minute class where the instructor writes on the board and students copy what the instructor writes, we have used the following approach:

1)       Students are assigned sections from the textbook that are to be read before class starts.

2)      A short on-line, graded reading quiz (3-5 questions, usually multiple choice), based on the assigned reading, is due 2 -3 hours before class starts. The instructor views the student responses before class and adjusts what might be discussed in class (i.e. just-in-time teaching).

3)      Class time is devoted to students responding to multiple-choice conceptests. The students answer individually using personal response systems (clickers²). The objective is to use conceptests that approximately 30-40% of the students answer correctly on their own. That is, the main objective is not to test students but instead spend class time on topics that are confusing to the majority of the class.

4)      Students then discuss their answers in small groups (peer instruction^1,3,4) and can change their answers. The final answer is graded.

5)      Students and the instructor discuss the reasons for the correct answer and often the misconceptions students may have when choosing the wrong answers.

6)      Students then ask questions related to the concept in the conceptest. The instructor might present additional information related to the concept.

7)      Screencast videos⁵, many of which are solutions to example problems or explanations of conceptests, are made available for each chapter to replace/supplement materials that might have been used in class.

A typical class has 3-5 conceptests. We have used an on-line class management system (Blackboard) for collecting reading quizzes, and we use iClickers (www.iclickers.com) in class to collect the student responses to conceptests. The homework assignments contain traditional textbook problems and also some conceptual questions. The notes made in class and the conceptests are posted on line after class. Using a tablet PC instead of a board makes it easy to make the class notes available as a PDF file after class. The screencast videos are typically about 5-10 minutes long. They are similar to the solution of a problem that might be presented in class, but provide the students with the option to watch the video on their schedule, to stop and think about something, to replay parts, and to watch on a computer, iPad, or smart phone.  We have prepared them on tablet PCs, which allows stylus input to be continuously recorded while accompanied by dictation. They are not professional quality videos but instead are similar to the explanation that might be given in class.

We encourage other faculty to use the material that we have generated for this course in order to lower the barrier to adopting this approach to teaching material and energy balances. Our web site (www.learncheme.com) contains more than 200 conceptests and their explanations, and more than 75 screencasts. The screencasts are organized by topic and also by the table of contents of the Felder and Rousseau textbook. The screencasts are also available on iTunesU (search University of Colorado-Boulder or learncheme).  Since we began posting these MEB videos in August 2010, they have been watched more than 3,000 times.

Anonymous student feedback surveys during and after the course have been overwhelming positive. The majority of students find the screencasts “very useful” to “one of the best features of the course”. Similar, teaching class with conceptests and clickers has also received overwhelming positive feedback.  An example conceptest from material and energy balances is shown in Figure 1.

Fig. 1. An example conceptest.

The motivation for this active learning approach to teaching is to address what can be a major disconnect between engineering professors and their students.  Engineering students are visual, sensing, inductive, and active learners while their education, typically delivered through class lectures, had been auditory, sensing, inductive, and passive. Studies have shown that teaching with conceptests and clickers results in significantly enhanced learning^2-4.

  

References

1.      Mazur E. (1997). Peer Instruction: A User's Manual, Prentice Hall, Upper Saddle River, NJ.

2.      Caldwell J. E. (2007). Clickers in the Large Classroom: Current Research and Best-Practice Tips. CBE Life Sci Educ 6, 9-20.

3.      Smith M.K., Wood W.B., Adams W.K., Wieman C., Knight J.K., Guild N., and T.T. Su (2009). "Why Peer Discussion Improves Student Performance on In-Class Concept Questions", Science, 323, 122-124.

4.      Crouch C.H. and E. Mazur (2001). Peer Instruction: Ten Years of Experience and Results, Am. J. Phys., 69, 970-977.

5.      Falconer J.L., deGrazia J., Medlin J.W., M. Holmberg (2009). Using ScreenCasts in ChE Courses, Chemical Engineering Education 43, 286-289.

Acknowledgments

We gratefully acknowledge support by NSF-CCLI grant DUE-0920640, by Shell Oil, and by the College of Engineering and Applied Sciences, Engineering Excellence Fund at the University of Colorado.