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Of all instructional methods, lecturing is the most common, the easiest,
and the least effective. Unless the instructor is a real spellbinder,
most students cannot stay focused throughout a lecture: after about 10
minutes their attention begins to drift, first for brief moments and
then for longer intervals; they find it increasingly hard to catch up on
what they missed while their minds were wandering; and eventually they
switch the lecture off altogether like a bad TV show. McKeachie [1]
cites a study indicating that immediately after a lecture students
recalled 70% of the information presented in the first ten minutes and
only 20% of that from the last ten minutes.
There are better ways. Actively involving students in learning instead
of simply lecturing to them leads to improved attendance, deeper
questioning, higher grades, and greater lasting interest in the subject
[1,2]. A problem with active instructional methods, however, is that
they sound time-consuming. Whenever I describe in workshops and seminars
the proven effectiveness of in-class problem-solving,
problem-formulation, trouble-shooting or brainstorming exercises, I can
always count on someone in the third row asking---usually sincerely,
sometimes belligerently---"If I do all that, how am I supposed to get
through the syllabus?"
I have a variety of answers I trot out on such occasions, depending on
my mood and the tone of my questioner, but they mostly amount to "So
what if you don't?" Syllabi are usually made up from the standpoint of
"What do I want to cover" rather than the much more pertinent "What do I
want the students to be able to do". When the latter approach is
adopted, it often turns out that large chunks of the syllabus serve
little educational purpose and can be excised with no great loss to
anyone. But never mind: let's accept---for the remainder of this column,
at least---the principle that it is critically important to get through
the syllabus. Can I (asks my friend in the third row) use any of those
allegedly powerful teaching techniques and still cover it all?
Yes (I reply), you can. Here are two techniques for doing it.
In-class group problem-solving
As you lecture on a body of material or go through a problem solution,
instead of just posing questions to the class as a whole and enduring
the subsequent embarrassing and time-wasting silences, occasionally
assign a task and give the class one or two minutes to work on it in
groups of three to five at their seats. For example:
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• Sketch and label a flow chart (schematic,
force diagram, differential control volume) for this system.
• Sketch a plot of what the problem solution should look like.
• Give several reasons why you might need or want to know the
solution.
• What's the next step?
• What's wrong with what I just wrote?
• How could I check this solution?
• What question do you have about what we just did?
• Suppose I run some measurements in the laboratory or plant and the
results don't agree with the formula I just derived. Think of as
many reasons as you can for the discrepancy.
• What variations of this problem might I put on the next test?
(This and the last one are particularly instructive.)
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You don't have to spend a great deal of time on such
exercises; one or two lasting no more than five minutes in a 50-minute
session can provide enough stimulation to keep the class with you for
the entire period. The syllabus is safe!
Warning, however. The first time you assign group work, the introverts
in the class will hang back and try to avoid participating. Don't be
surprised or discouraged---it's a natural response. Just get their
attention---walk over to them if necessary---and remind them
good-naturedly that they're supposed to be working together. When they
find out that you can see them(1) they'll do it, and by the time you've
done three or four such exercises most of the class will need no extra
prodding. Granted, there may be a few who continue to hold out, but look
at it this way: in the usual lecture approach, 5% of the students (if
that many) are actively involved and 95% are not. If you can do
something that reverses those percentages or comes close to it, you've
got a winner.
In-class reflection and question generation
The one-minute paper is an in-class assignment in which students
nominate the most important and/or the most confusing points in the
lecture just concluded [3,4]. Variations of this device can be used to
powerful effect. About two minutes from the end of a class, ask the
students---working individually or in small groups---to write down and
turn in anonymous responses to one or two of the following questions: |
• What are the two most important points
brought out in class today (this week, in the chapter we just
finished covering)? Examination of the responses will let you
know immediately whether the students are getting the essential
points. Also, when the students know beforehand that this question
is coming they will tend to watch for the main points as the class
unfolds, with obvious pedagogical benefits.
• What were the two muddiest points in today's class (this week's
classes, this section of the course)? Rank the responses in
order of their frequency of occurrence and in the next class go over
the ones that came up most often.
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The responses to this question will surprise
you. What you would have guessed to be the most difficult concepts
may not show up on many papers, if they show up at all; what will
appear are concepts you take for granted, which you skimmed over in
your lecture but which are unfamiliar and baffling to the students.
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• What would make this material clearer
to you? You also never know what you'll get in response to this
one---perhaps requests for worked-out examples of solution
procedures or concrete applications of abstract material, or pleas
for you to write more clearly on the board, speak more slowly, or
stop some annoying mannerism that you weren't aware you were doing.
Responses to this question can provide valuable clues about what you
could do to make your teaching more effective.
• Make up a question about an everyday phenomenon that could be
answered using material presented in class today (this week).
(Optional:) One or two of your questions will show up on the next
test.
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I used the last exercise---including the zinger
about the next test---at the end of a course segment on convective heat
transfer and got back a wonderful series of questions about such things
as why you feel much colder in water at 20 degrees celcius than in air
at the same temperature; why you feel a draft when you stand in front of
a closed window on a cold day; why a fan cools you on a hot day and why
a higher fan speed cools you even more; why a car windshield fogs up
during the winter and how a defogger works; and why you don't get burned
when you (a) move your hand right next to (but not quite touching) a pot
of boiling water; (b) touch a very hot object very quickly; (c) walk
across hot coals. I typed up the questions (sneaking a few additional
ones onto the list) and posted them outside my office---and in the days
preceding the test I had a great time watching the students thinking
through all the questions and speculating on which one I would put on
the test. (I used the one about the fan.)
There are other short, easy, and effective instructional methods, but
these should do for starters. Check them out and let me know how they
work for you. If I collect some good testimonials (positive or negative)
I'll report them in a future column.
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References
1. McKeachie, W.J., Teaching Tips, 8th Edn. Lexington, MA, D.C.
Heath & Co. (1986).
2. Bonwell, C.C., and J.A. Eison, Active learning: Creating
Excitement in the Classroom, ASHE-ERIC Higher Education Report No.
1, Washington, DC, George Washington University, 1991.
3. Wilson, R.C., "Improving Faculty Teaching: Effective Use of
Student Evaluations and Consultants," J. Higher Ed., 57, 196-211
(1986).
4. Cross, K.P., and T.A. Angelo, Classroom Assessment Techniques: A
Handbook for Faculty, Ann Arbor, National Center for Research to
Improve Postsecondary Teaching and Learning, 1988.
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Source: Felder, Richard, "How About a Quick One?"
Chem. Engr. Education, 26(1), 18-19 (Winter 1992).
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