Motivating Students to
Learn Physics Using an Online Homework System
John Risley
The Issue -
A major task of physics teachers is to encourage students to solve
physics problems. Traditional tools such as textbooks, lecture time,
tutorial centers, and tests can help, but more creative effort is
required to give them the practice they need to master new concepts
and applications. Although we identify important problems for our
students to consider, assign a schedule, and answer questions to
help guide them through the intricacies of an expert solution, students
are reluctant to expend the time and energy required to complete
the work.
If these assignments
are not graded, at best the students will simply look over the list
of problems. We can tell students that solving these problems will
help them on tests, but in reality little is done except last-minute
cramming the night before the exam. Routine assignments with deadlines
are necessary for most students to learn physics. But this work must
be graded if it is going to encourage students to spend time working
through the exercises. Grading is a chore, and many teachers simply
do not have the time or resources to grade papers carefully.
This critical grading
task can be virtually eliminated by using online homework grading
systems. Students will receive immediate feedback, and instructors
can offer more frequent, shorter assignments to keep students up
to date on the course material.
A robust, multifeatured
system with a richly endowed question database is critical to successful
online grading. One such system is WebAssign, a web-based homework
delivery, collection, grading, and recording service available to
teachers, professors, and instructors who want to provide more effective
encouragement to their students learning physics, see http://webassign.net.
WebAssign -
WebAssign delivers, collects, scores, and records student work. Teachers
make up assignments by using their own questions or choosing questions
from leading physics textbooks. WebAssign is a project in the department
of physics at North Carolina State University (NCSU). It is supported
by a team of programmers, content specialists, editors, designers,
and instructors. New features and improvements are deployed continuously
to provide the best possible assessment system. Agreements with textbook
publishers are in place that allow WebAssign to deliver problems
from class-adopted textbooks. New agreements are sought continuously
as new textbooks and editions are published.
The origins of
the WebAssign code stem from work conducted by Larry Martin, a physics
professor from North Park University in Chicago, and Aaron Titus,
a graduate student in physics education research at NCSU. Larry Martin
wrote a comprehensive web-based homework system using a flat file
architecture. He created the tag, which is a way to incorporate
powerful Perl functionality into questions and answers. This tag
allows you to randomize numbers, variables, and many other programming
features such as logic statements, define variables and arrays, etc.
In May 1996, Aaron Titus created a web-based assignment system using
a database of questions and answers delivered by a Macintosh server.
This system was used with 300 students at NCSU. Martin and Titus
collaborated in 1997-1998 to develop the basic functionality of the
current WebAssign system. This merger led to a very robust, multi-featured
application.
Many individuals
are involved with WebAssign so that the features instructors want
can be added to the system. A high level of responsiveness demands
a concerted effort by faculty, programmers, editors, and technical
support associated with the project. WebAssign is offered as a fee-based
subscription service to teachers at universities, secondary schools,
and educational institutions to provide viable funding for this work.
WebAssign offers
many key features that are important for physics teaching. The most
significant is the quality of its question types. Numerical
questions can be randomized with answers that depend on
the calculated values, and even answers that depend on values that
the student enters. Students receive the same set of questions, but
each will have different values. Symbolic questions allow
a formula to be entered, again with randomization of numbers and
variables. Java applets, such as the Physlets from
Wolfgang Christian at Davidson College, can be deployed to offer
a very different kind of problem to solve. These simulations bridge
the gap between questions about a static drawing to a laboratory
measurement, while maintaining the advantage of automatic grading.
A file-upload question type is available for grading Excel spreadsheets,
Word documents, a MatLab worksheet, or any other type of file. Multiple-choice,
multiple-select, and fill-in-the-blank questions are also available.
All questions in
WebAssign can utilize Martin's powerful <equ> tag, which
allows a teacher to write code in Perl and have it evaluated in WebAssign.
This important development also enables teachers to write questions
that can analyze students' experimental parameters and their resulting
calculations. With the full power of a programming language hidden
just beneath the question, physics teachers can offer all sorts of
logical statements and conditions for questions and answers.
A hallmark of WebAssign
is its extensive database of questions from leading physics textbooks.
In WebAssign, it is easy to create elaborate multipart questions,
which can represent exactly the questions found in textbooks. Coding
questions is an intensive task, requiring careful attention to detail
and accuracy. An incorrectly coded answer algorithm can cause much
grief with students, so the WebAssign team responds quickly when
these kinds of problems arise. WebAssign supports textbook questions
with a quick turnaround time for reported error. This responsiveness
sets WebAssign apart from other online homework systems.
The questions coded
into WebAssign are virtually an exact replica of the original question,
using the same figures and pictures that appear in the textbook.
As teachers, we know how easily the scope of a question can change
with just a slight alteration in wording. By working with leading
publishers ,WebAssign has taken a strong position on providing the
very highest quality set of textbook questions.
WebAssign's
Publishing Partners
WebAssign offers
numerous student communication links for the teacher. In addition
to offering the capability to email one student, a group of students,
or the whole class, WebAssign has a "help desk" that allows
students to request help with a specific assignment. A teacher can
respond to these questions efficiently because a full display of
the assignment, along with the student's responses and correct answers,
is available from the help desk. This is much better than having
students send you an email about an assignment that you then have
to look up!
Reporting grades
is an important component in a teacher list of responsibilities.
WebAssign shows all scores, down to each individual problem, for
any and all assignments. All of the relevant statistics are available
for any question or assignment, such as average, mean, max/min, standard
deviation, or index of discrimination.
One Example -
Each teacher can adapt WebAssign to suit his or her particular needs.
This is what makes WebAssign such a powerful tool. For example, I
will outline how Bob Beichner and I use WebAssign for both of our
introductory calculus-based physics courses at NCSU. This course
is taught in the SCALE-UP classroom with the able assistance of Jeanne
Morse, my TA. (Our more typical lecture courses with laboratories
also make heavy use of WebAssign, but without the added advantage
of having computers in the classroom.)
Each week we assign
two homework problem sets. They are due one hour before class. (We
have found that midnight deadlines don't work, since many students
start the assignments in the middle of the night, and a deadline
too close to the start of class results in students coming to class
late!) On Mondays, the assignment consists of three to four easy
questions from the textbook, usually focusing on new material that
we have not covered in class. This forces students to read ahead
and prepare for the upcoming class. Students are certainly better
prepared now. The Wednesday assignment covers the more difficult
questions and might have four to six questions. At the start of each
class, we often have lively discussions about the homework. For students
who had difficulty, these discussions bring them up to speed and
they usually ask for an extension to resubmit their work so they
can get a perfect "100." I generally allow extensions.
I want to encourage my students to spend more time learning physics,
and with WebAssign an extension doesn't require any more time from
me to grade their work. (WebAssign easily facilitates extensions,
and you are notified whether or not the student has seen the answer
key.)
On Fridays, we
give in-class quizzes using WebAssign. We have a classroom filled
with computers so the task is very efficient. WebAssign has security
controls that allow you to restrict access until a password is given
in class and allow only certain computers access based on IP subnets.
We often have in-class
activities, similar to a laboratory, but shorter. To encourage students
to think about the work before coming to class, we post a prelab
assignment on WebAssign that is due before the lab. The formal lab
is a group effort, written in Word or some other word processor.
Any member of the group can upload it into WebAssign as a file-upload
type. The TA is able to read the electronic reports, assign a score
in WebAssign, and give comments to the group that become a permanent
record for each student. We also assign a few problems about the
lab that can be graded automatically. WebAssign allows you to create
automatically graded questions that ask the student to enter their
measured values, assess them for reasonableness by setting a large
tolerance, and then use their measured values to calculate some physics
property. The essential data taking and analysis can be graded accurately
and automatically. If you give students multiple submissions, they
can correct mistakes made during data acquisition as they complete
the analysis portion of the lab. It is also possible to freeze the
acquired data in one assignment and then use that data in the analysis
section so that students are less likely to fudge their results!
Computer simulations
are a very effective way to get students to interact with physics
concepts. The trouble, though, is that students will not use the
simulations effectively unless you ask them some leading questions
that can only be answered through careful observation. If you do
not ask students to turn in their observations for grading, the students
do little work. We have used a number of java applets for in-class
activities that are graded either on the spot or just after the class
is over. Again, by automatically grading the students' work, you
can be certain that they have been engaged in the learning opportunity.
Finally, we use
WebAssign for high stakes testing. Here, the benefits of automatic
grading are obvious. For a typical 50-minute exam, we deploy about
ten questions, many with subparts. They range from very simple calculations
and multiple-selection conceptual questions to difficult computations.
To encourage students to think hard about the content of the test,
we allow two "free" submissions. This way, if students
make a simple mistake in their calculations, they can correct it
with the second submission. To encourage struggling students, we
offer additional submissions but with a loss of 3 points, out of
100 maximum, for every additional submission. We are happy with the
results. Students who know the material receive high scores and those
who are not putting in the appropriate effort get low scores. Student
surveys indicate a high degree of satisfaction of WebAssign tests
over our standard multiple-choice tests.
We recognize that
our use of WebAssign is not entirely typical. However, we have seen
that it saves time while motivating students to do the work. What
more could we ask?
John Risley,
professor of physics at North Carolina State University, is well
known for his research on the utilization and effectiveness of
computer technology to teach physics. He is editor of Physics Academic
Software, a cooperative effort with APS, AIP and AAPT, and he is
director of WebAssign. His email address is: John_Risley@ncsu.edu
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