(455a) Not Lecturing In a Material and Energy Balances Course

Falconer, J. L., University of Colorado Boulder

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
learning1-5 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:

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

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).

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.

then discuss their answers in small groups (peer instruction1,3,4)
and can change their answers. The final answer is graded.

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

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

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.

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.

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.

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.


An example conceptest.

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 learning2-4.


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
Education 43, 286-289.


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.