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A Gentler Discovery Method, Wm. Ted Mahavier
I believe that the most common mistake made by teachers is that we forget what our
principal objective should be. We walk into the classroom saying, "Here is the
syllabus that I must cover this semester," forgetting that the need in the classroom
is to prepare the student to handle the situations that arise after leaving the classroom.
As teachers, we place too much emphasis on the material we "must" cover at the
expense of teaching students how to learn on their own. Suppose that a student graduated
knowing every fact he were taught. Will these facts be sufficient for success as the
student enters the work force or graduate school? Surely not. More likely, the problems
the student faces will require learning new material specific to the task at hand and then
the application of some of these previously learned facts in conjunction with the new
material. The key to whether the student succeeds or fails is his ability to learn on his
own.
Mathematics teaching-reform methods fall into one of several categories: introducing
technology into the classroom, collaborative learning, and methods such as the Harvard
calculus techniques where traditional material is replaced with new material. The method
offered here is a gentler type of reform than these controversial methods (Wilson, 1997)
being hailed by many reform enthusiasts. It allows the teachers to develop as many or as
few new materials as they choose and to involve students interactively in the class as
much or as little as is appropriate for the course being taught. These qualities make
implementing the method less traumatic for both teacher and student. Specifics are
discussed in the section entitled "A Course Description."
The method advocated in this paper is a derivate of the method referred to by the
mathematical community as the Texas method or simply Moore's method, after the founder, R.
L. Moore, who produced a long list of successful mathematicians (called
"Texans") during his tenure at the University of Texas (Moore). The heart of his
technique was to provide students with a very carefully selected sequence of problems and
theorems that enabled them to prove and present the material for the class. The modified
Moore method, which I use and propose, limits the amount of presentation done by the
students to make the method accessible to lower level classes and to facilitate using
traditional materials and texts while still emphasizing student presentation. This method
fits well with the current reform movements directed toward involving students more
actively in the learning process. It prepares students for academia as well as industry by
encouraging communication skills, presentation skills, critical thinking (the latest
reform buzz-word for "thinking"), and writing skills while alleviating many of
the difficulties that we experience as teachers, such as complacent students, students
with poor work ethics, (seemingly) low-quality students, and students with low test
scores. Further references for the method and the author's exposure to the method are
outlined following the body of the paper.
Actively involving the students in the material is fundamental to learning. I defy you to
teach a student to ride a bicycle by lecturing at the blackboard. The student must get on
the bicycle and fall. The natural athlete will fall once and then, with a few words from
the instructor, successfully ride. The lesser athlete will fall a few times and become
frustrated. At this point, the instructor must step in and guide the student, again,
through some basic theory of balance, brakes, and pedaling, perhaps demonstrating via
example. In a few more attempts, the student will be cycling -- thanks to the teacher and
Moore's method.
The method of try, fail, and try again, which is so integral to the Texas method, is
illustrated by the famous (among Texans) talk by Dr. M. E. Rudin in which she discussed
why she was not going to prove a certain theorem. It seems she found a mistake the day
before she was to present the paper and proved the converse of what she had stated. Even
the best fall off the bicycle occasionally. That is part of learning. We try, we fail, and
we try again. It is this fact that makes the Texas method so successful in the classroom.
Students work on problems that are difficult, have some measure of success, discuss the
problem with the teacher, and attempt the problem again. Does this sound like academic
research and research in industry? It should, and it should start in the classroom rather
than upon graduation.
Having students present work is one way to cure the problem of emphasizing the syllabus
over teaching students to learn. There are a number of advantages to having students put
problems on the board. First, the presentation itself is representative of what a student
will do in the future. In industry, briefings are standard formats for conveying
information, while in academia, presenting papers is an extension of putting problems on
the board. Second, the board is a great leveling field; students who may have done quite
poorly in other classes (perhaps due to time pressure on exams) are now able to prepare
for and present material that they have taken the time to fully understand, thus building
some measure of confidence. Third, students learn the necessary mathematical rigor
required to convey something that they understand to their classmates. What is clear to
the student may not be clear to the audience. In other words, students develop the skill
that is the single-most cited attribute that industry seeks when hiring: communication.
Finally, the course automatically adjusts to the level of the students. The constant
contact with the students alerts me early on to the level of a class. With a weaker class,
I will go into less detail in certain areas, while in a stronger class I am able to
address additional topics of interest. In many instances, this allows me to alleviate the
concern over covering the syllabus that I addressed earlier, since, with a weaker class, I
go into less detail and can still complete the syllabus for the course.
Having hailed the benefits of the method, I offer one caveat. I rarely call the method I
use the Texas method for two reasons. As a "second generation Texan," I cannot
say how closely my methods model those of the late R.L. Moore, and I believe there has
been a prejudice against the method in the past. Years ago, I remember a professor saying
that he believed there was a move afoot to systematically destroy the method. However,
while interviewing for assistant professor positions, I found department heads very open
to what I had always considered radical teaching methods. I believe the prejudice stems
from the fact that the Texas method is often misunderstood and poorly implemented.
Perhaps I am not qualified to judge the teaching of a man I never met, yet the multitude
of classes I took under Texans lead me to certain conclusions. It is my opinion that many
of Moore's students believed his method could be described merely by the structure of the
course. Problems or theorems are passed out and students present these problems at the
board after they solve them. Each class period, volunteers are taken and a pecking order
is established. Unless the students are unusually uniform in both mathematical background
and talent, this often leads to strong students rising to the top and presenting a
majority of the material, while weaker students fall and are subjected to what is
essentially a lecture class conducted not by an experienced Ph.D., but rather by other
students. If this were Moore's method, then I too am a critic. Yet, I believe this was not
his method. I believe Moore to have been as much psychologist as teacher (as most good
teachers are), carefully analyzing each student's abilities and providing guidance in such
a way that students with a wide range of abilities achieve some measure of success. To
clarify further, I describe two Texas classes that I took as a student. I can say without
question that these were the two courses in which I learned the least and the most
mathematics.
I took the first course as an undergraduate. The class was composed of mathematics
education majors, mathematics majors, and a few mathematics graduate students. The class
started with about thirty students and by the end of the second quarter (of three) only a
few students were presenting material. While the class seemed of little value to a
majority of the students, at least one student in that class went on to receive his
doctorate quite rapidly. For him, this class had been a stepping stone to higher
mathematics, albeit at the expense of the other students. A case could be made that this
was a valuable course by that standard. On the other hand, several students from that
class, myself included, were steered away from mathematics, at least temporarily, by the
experience.
The second course was taken at the graduate level. I can honestly say that through this
course, I gained the skills that enabled me to obtain my doctorate. In this class, the
range and level of the problems was such that a large percentage of the students put
theorems on the board. In fact, out of twenty starting students, at least six went on to
receive doctorates. And again the top students in the class excelled and truly used the
class as a stepping stone from the mundane regurgitation of mathematics to the sheer
beauty of proving theorems and doing mathematics on their own. This time a Texas course
had set me on route to my doctorate.
Assuring that a large percentage of the class is presenting on a regular basis may be
accomplished by assigning sufficiently many accessible problems for lower-level students,
by offering individual help via office hours, and by having students submit problems in
written form that may be presented at the board after corrections are made. I have used
all of these techniques to level a class of diverse talents. A more controversial
technique that I use is to delay the presentation of a problem that a bright student has
if no other student has a presentation to offer. This gives the class a day or so to catch
up and assures that the course will not become a lecture course "taught" by one
or two advanced students. Quite commonly, two students will come by my office on the same
day and query me concerning the same problem only to receive very differing amounts of
guidance in order to give them a somewhat equal opportunity to present the problem. Using
these techniques allows students with a wide range of talents to achieve their personal
best in my classes.
The question remains, how does one adapt such methods to classes ranging from freshman
college algebra to graduate courses? In (Smith), Michel Smith notes that the method seems
considerably more effective at the higher levels. I would argue that this is true of any
teaching method. More mature students make for better classes. On the other hand, his
calculus course was a true inspiration and starting point for me to develop the modified
method that I describe below. Because the traditional Moore methods are quite applicable
at higher levels and have been implemented for years with success by teachers too numerous
to list here, I offer the description of a lower-level course that I have taught
successfully over the past eight years at institutions ranging from Cooke County Community
College to Emory University. The method naturally adjusts itself to the level of the
students. I would call it a modified Texas method. This strategy has been applied
successfully in the following courses: Algebra, Trigonometry, Pre-calculus, Business
Calculus, Calculus I, II, Differential Equations, Graduate Ring Theory, and Graduate
Numerical Analysis. While I won't say that it went perfectly the first time I tried it, I
will say that, from the first attempt, it was clear that it was a method of merit and that
the classes were better than in my traditional-style lecture classes.
A COURSE DESCRIPTION:
From freshman to graduate-level courses, I send students to the board. This may take as
little as 25% of class time or as much as 95% of class time. Generally, the percentage of
time a class spends at the board increases with the level of the class, the exception
being when the class has an applied aspect such as numerical analysis. For example, a
three- hour-a-week calculus class will spend only one hour a week at the board while a
three-hour graduate numerical analysis class will spend about half the class time at the
board, and an undergraduate introductory analysis class will spend virtually all of the
class time at the board.
Why so varied an amount of time? Because an argument can be made that for certain
(prerequisite) courses, having a large body of knowledge on a subject is as important as
having a deep understanding of the subject. In my freshman and sophomore level classes, I
feel that covering a certain amount of material is a necessity since the students may not
get a proponent of the Texas method in the following semester, and lecturing facilitates
this goal. In my graduate numerical analysis classes, I feel that I am responsible for
covering a wide range of topics so that the students will be well-versed in numerical
techniques. Yet in my analysis class, I feel that depth of understanding is crucial at
this stage, since this is where students will either learn how to prove theorems or fail
to become mathematicians and this class has almost no lecturing.
Grading: The student averages come from three tests (50%), homework presented in class
(25%), and a comprehensive final (25%). All problems in my class receive a grade of 0-3
where, 0 = wrong, 1 = mostly wrong, 2 = mostly right, and 3 = right. I like this rather
harsh grading system since the student who gets every problem on every test mostly right
and receives an "A" on homework has a "C" average. Clearly students
strive for better than "mostly right" on their work. Grading flexibility is
important, and I admit to students that high homework averages or high final exam grades
can raise their final grade above their computed average. At the end of the semester there
are inevitably students with "D" averages and "A" on homework. Such a
student receives a "C." Also there are students who were bright enough never to
come to class for homework days, but have an "A" average on the tests and final.
These students receive "A"s, despite an "F" on homework.
Grading flexibility is one of the goals of the method; having interacted with the students
all semester, there are inevitably students whose grades do not reflect their mathematical
ability. Perhaps they spent too much time exploring alternate ways of solving problems
(researching) and not enough time practicing mundane problems. Without the interaction,
such students go unnoticed. It has been said that calculus should be a pump, not a filter.
This method supports the idea that we should be spending our time catching the good
students rather than filtering out the bad.
Structure: I lecture on Monday and Wednesday, assigning problems as I go, and the class
presents these problems on Friday. A normal class period has lots of questions because
students know that this may be the only source that can help them prepare for the homework
I am assigning. There are two definite benefits of assigning problems as I lecture. First,
it encourages the students to look over their notes, they must in order to find the
homework problems, and second, it assures that I have assigned problems on all the
important aspects of a topic. In addition to these problems, I often assign problems from
a text. If a student can do every problem I assign at the board, then there is no need to
open the text; however, only the brightest of students find this to be the case. The vast
majority need practice and they find that practice in the problems I assign from the book.
Since I rarely discuss the book, they must decipher other notations. This encourages using
the book as a reference rather than a bible. The students need to understand my problems
and the book is a possible source of help in doing this. Since I rarely write out my
problems beforehand, students must interact with one another to find homework assignments
from days they missed. As a consequence, I have good attendance in my classes and good
student communication. Cooperative learning would be the reform buzzword.
TGIF! It is Friday and we are ready to go to the board. As I call on students and assign
problems for them to present, the first students immediately go the the board and put
their work up simultaneously. They are allowed (expected) to take their notes and use
them. Every problem I assign makes it on the board, so I generally only assign about
twenty problems a week and send students to the board five at a time. Each student
receives a grade based on the scale previously mentioned.
In truth, I am quite soft on homework grading. For example, if a student does not have the
problem they are called on to present, I will let them do another problem of their choice
for one point less. Also, I record a grade of "3" as I call on them and only
mark them down for rather serious mistakes, despite what I have told them.
While the students are putting the problems on the board, I answer questions from the
students at their seats, but they must vocalize the problem. They may not show me their
work. I may also wander the room asking for questions and encourage them to discuss among
themselves the mathematics. After the problems are on the board, any students who have
questions on the material are encouraged to speak up. I generally ask if they agree with
the answers and let students point out mistakes. I don't check every step if the class
agrees the problem is right and there are no questions. In fact, I go so far as to tell
them that I will not check every step, so they need to in order to verify what is wrong.
This way students with incorrect answers will say, "I didn't get that," and we
will look more carefully at the problem. Note the self-adjusting nature of the course. If
only a few students have the homework, then I am teaching over their heads, while if
almost all the students have the work then I can assign harder problems and move faster.
I readily admit that one of my goals in developing this course was my own enjoyment of
teaching. I firmly believe that professors who enjoy teaching are good teachers and I look
forward to walking into my classroom every day. But I do not enjoy long hours of
preparation, grading homework, or grading quizzes. In order to make the class more
enjoyable to myself, I want to spend more time interacting with the students and less time
on class preparation, grading, and office hours. By lecturing virtually without a book,
changes in texts do not add preparation time to the course. Assigning problems as I go
requires minimal preparation time as well, although some preparation must be taken to
assure they are reasonable problems. Finally, by encouraging questions in class, answering
the same question from several students during office hours is minimized. I have found
that walking into class without notes or a book catches the students attention. Students
are not stupid and they recognize that I am not reading a section and then regurgitating
it. Rather, I am guiding and directing the course based on their questions and interests.
Because of this they enjoy the class. Because they enjoy the class, they work hard on it.
What more can we ask of a class, but that the students enjoy it and learn a lot of
mathematics?
I recall the first day I walked into a classroom to teach. After a typical introduction, I
started at the board as nervous as I'd been in years. Three- fourths of the blackboard was
full and I recall thinking to myself, as I continued to lecture, that I would be teaching
at least for the remainder of this semester, probably another, and possibly for the rest
of my life. It was time to shed my nerves and relax. I turned to look at my students, only
to find them hopelessly nervous and writing frantically. I asked, "How many of you
understood what I have said so far?" Two hands went up. I erased the board, told them
to tear out the notes they had taken, and started over. I promised I would not erase
anything from the board in the future until they understood it -- and do you know what
happened? They believed me. My first class was a lot of fun for me, and my willingness to
talk with rather than at the students and to alter my course based on their responses has
guided my teaching philosophy ever since. The course that I described is a credit to my
students' honest responses to the questions I have asked them over the past nine years in
person and on evaluations.
Good luck. And remember, interactive teaching is not only good teaching, it is enjoyable
teaching.
REFERENCES:
Perhaps the best description of Moore's method is given in his own words in the video tape
produced by the Mathematical Association of America, (Moore). An accurate description of
the method is also given in (Halmos, 1985). In (Mahavier, 1996), the author describes a
graduate applied numerical methods course that utilized a modified Texas method so that
the course could include a large quantity of material, including programming, applied
mathematics, and pure mathematics. For references concerning upper-level undergraduate
courses utilizing the Texas method, consider (Mahavier, in preparation) and (Wilf, 1996).
See (Euda, 1996) for descriptions of effective techniques in classes where students learn
to prove theorems. (Chalice, 1995) describes a method of addressing the often-cited
problem of covering a reasonable amount of material in Texas- method courses by sending
many students to the board simultaneously on less difficult problems prior to sending them
to the board one at a time for difficult problems.
PERSONAL NOTE and BIOGRAPHY:
My teaching methods are largely a product of the many superb courses I took over the years
and my exposure to the Texas method was vast. Michel Smith's calculus class at Auburn
University caused my change in major from physics to mathematics. It was my father, W. S.
Mahavier, whose examples led me to teach via Moore's method. Paul Lewis taught me more
about mathematics and teaching mathematics than anyone, and John W. Neuberger, a man whose
infinite optimism is an inspiration to all who know him, directed my doctorate. While I am
a firm believer in the method and my education was largely guided by "children"
and "grandchildren" of R. L. Moore, H. S. Wall, and H. J. Ettlinger, I remain a
strong supporter of other methods, perhaps because a non-Texan, Dean Hoffman, set the
stage for my return to graduate school by gently convincing me that I could prove
theorems. I feel deeply indebted to my teachers and I repay them in the only way I can, by
carrying their examples into my classroom and passing the time they offered me onto my own
students. I am currently an Assistant Professor at Nicholls State University, Thibodaux,
LA 70310, and may be reached via e-mail at math- wtm@nich-nsunet.nich.edu.
Chalice, D. R., "How to teach a class by the modified Moore method,"
Amer. Math. Monthly, Vol. 102, #4, April 1995.
Euda, D. E., "Teaching the Proof Process," College Teaching, Spring
1996, Vol. 44/No. 2.
Halmos, P. R., "I Want to be a Mathematician," Springer-Verlag, 1985. p.
255- 265. Mahavier, W. S., "Teaching Mathematical Creativity," in preparation.
Mahavier, W. T., "Interactive Numerical Analysis," Creative Math Teaching,
August 1996.
Moore, R. L., "Challenge in the Classroom," Mathematical Association of
America Video Tape.
Smith, M., "Learning and Teaching Mathematics via Discovery," in
preparation.
Wilf, H. S., "Epsilon Sandwiches," FOCUS, Vol. 16, #2, April 1996.
Wilson, Robinson, "A Decade of Teaching `Reform Calculus,' Has Been a
Disaster, Critics Charge," The Chronicle of Higher Education, Vol.
XLIII, #22, February 7, 1997.
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