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25 June 2012

Online Homework: I don't suggest unless you're desperate

Time to tackle one of the more frequently asked questions... Noah Segal, of Trinity School in New York, writes in to ask:

Have you tried an online homework system (e.g. WebAssign, WileyPlus, MasterPhysics, etc.)? If you’ve had experience with more than one of them I’d like to know how they compare. If you have tried one and went back to paper-based hw, that’d be valuable to know as well.

While I'm not thoroughly versed in the history of online homework systems, my understanding is that they developed in introductory university courses populated by hundreds of students each term.  There, the principle is sound: a professor can't possibly grade 350 homework assignments, and hiring student graders presents issues of cost, logistics, fairness, and competence.  Requiring online submission not only eliminates the headache of grading, it allows the professor to assign work more regularly, and to tell at a glance who is keeping up. Online homework is much, much better for such a professor than the alternative, which is, essentially, unevaluated homework. 

Once colleges started raving about online homework, the software providers decided to penetrate the high school market.  But for high schools, the cost-benefit analysis shifts.  I believe that in virtually all cases, online homework is an expensive, useless toy -- at best, technology for technology's sake; at worst, a lazy teacher's destructive, wrongheaded message about what physics problem solving is all about.

Drive to the heart of the matter:  what's the fundamental point of physics homework, anyway?  I don't assign homework just because it's a school expectation, or because I need to enter a grade into a grade book... homework problems are like football practice, designed to prepare students for the rigors of a game / test.  I'm making the class engage in the difficult, novel process of physics problem solving.  Homework provides a low-pressure chance to try out the types of problems they'll face on tests, but in a setting where collaboration is encouraged and help is available when they get stuck, and where losing credit for misconceptions is not really a big deal.

By grading through a stack of paper homework, I can tell who's keeping up, I can bring in students to extra help who need it, I can enter a grade in the gradebook.  But I can also use my grading to help communicate expectations and good ideas about problem solving.  Johnny didn't include a free body diagram on this equilibrium problem: he lost credit, which sent the message that "free body diagrams are an awesomely good idea" far better than nagging.  Jimbo did everything right, but got the answer wrong due to a calculator error:  he got almost full credit, more credit than Johnny did, sending the message that "the precise answer is subordinate to the process in introductory physics."  Joe got everything right, but his paper was identical to Frank's in every way: both Joe and Frank had to redo the assignment in extra help, and were politely reminded that pure copying is inappropriate and could result in trouble.

Thing is, on webassign, Johnny got full credit 'cause his answer was right.  He wasn't so happy a week later when he couldn't figure out a test problem that couldn't really be done without the free body.  Jimbo was marked wrong, and got frustrated, thinking he didn't understand the physics, even though he had done outstanding work.  Joe couldn't copy off of Frank, 'cause webassign randomized the input values to the problem; so Frank just showed Joe how to plug the different numbers into his final equation, and Joe got full credit for using a calculator blindly with Frank's work.  How that's different from copying, I'll never know.

I've been told that webassign and/or clones will, in fact, support conceptual questions requiring verbal justifications -- students type in their justifications, and the teacher can evaluate them online.  Well, um, that's pretty darned close to grading paper assignments.  If you think that's faster than collecting paper, okay... but I still have concerns about presentations.  Computer input doesn't allow for easy drawing of diagrams or writing of equations.  That's what unlined paper is for.

Now, there can be some benefits to webassign, even in high school.  If you can get past the sign-in issues,* you can check instantly for completion of some routine tasks.  Perhaps assign a quick question in which students need to plug-and-chug into the equation for the period of a pendulum.  Well, there's no escape for your class -- they have no choice but to look up the equation and use it to solve the problem.  You haven't taught any material, you haven't helped gain an understanding of pendulums, but you've made sure that the students have taken the first step toward at least recognizing and memorizing the correct equation, and that's a positive.  Perhaps you can use webassign to pose a couple of quick multiple questions that you would otherwise spend 5 minutes on at the beginning of class.  Great!  That's using technology to effectively replace something that would have required class time. 

I once visited a physics class early in the year, and most of the 40 minute period was spent answering student questions such as "I couldn't log in to my online homework account" and "once we log in, how do we input our answers, again?"

The question is, are these benefits worth the expense?  "Expense" includes not just money, but time and resources as well.  (Physics homework is less daunting to start if it requires only a blank page, not a webassign-enabled, networked electronic device.)  

So Noah, I strongly recommend against online homework system.  Just like learning physics is hard work, teaching physics is even harder.  Grading homework papers is, I think, an unavoidable and essential part of helping our students learn.  While there are tricks and techniques to reduce time spent grading, I don't think it's possible to eliminate or even minimize paper assignments.



  1. You make good points, but since you haven't tried it and gotten feedback from students about it, perhaps your confidence in your opinion is not fully merited.

  2. Fair point -- my opinion is educated, but not from personal experience.

    I would welcome comments, or even a full post, from someone who has used online homework and can specifically address my concerns above. I cannot see the costs of online homework justifying the benefits, at least in a typical high school situation. If you disagree (and, of course, if you have no financial stake in the matter), please rebut.


  3. I have used webassign for the past five years in Honors Physics 1 and AP Physics B. Another physics teacher at our school also uses it. Cost was a real issue the first 4 years, but our Principal graciously paid for the fee ($10.50 per student) this past year. For the first several years, we enjoyed watching informal homework study groups working on their webassign problems after class. This has mostly died off in recent years. We suspect that students are collaborating on the problems in other ways (Facebook, text messages, etc.). It is quite common to have students who score well on webassign, but demonstrate little or no ability to solve similar problems on tests. Our guess is that the collaboration between students has been reduced to sharing the "magic algorithm" to solve each problem. So, my experience confirms some of Greg's points. I imagine many students reaching the conclusion that doing physics means memorizing stuff to plug into your calculator.

    From time to time, I have used the logging feature within webassign to note the time students spend online. Weak students tend to wait until right before the deadline to download the problems, and devote much less total time than stronger performing students. However, most students do earn the points. This is another indication that the "help" the weak students receive is actually more like cheating.

    I think MIT physics professors developed an algorithm to predict which Freshman would eventually change into easier majors in their sophomore year. Basically, the less time a student spent on each question, the more likely they were to switch majors. In other words, deciding to cheat is their first act of desperation. Or perhaps, it is a cry for help. This seems like a clever use of these systems, but extracting this sort of data from webassign is very time consuming.

    Next year, I plan on backing away from webassign. If I can't convince my PLC partner to stop completely, and if the cost is covered by the Principal, I suppose I will continue to use it for some things. But webassign does not develop good problem solving skills, nor does it provide much insight to the teacher.


  4. Thanks for the comments, Anons. But why didn't anyone tell me that I had a spelling error in the title for a week? :-) Fixed now...


  5. I started using MasteringPhysics for my AP Physics C: Mechanics class two years ago. I'll say this about the cost: It was free! Since our school system had adopted a textbook from Pearson, I contacted my rep about MasteringPhysics and they sent me two codes: Teacher Code (which gave me full unrestricted access) and Student Code. The student code was valid for 45 (I think???) registrations. Meaning 45 different students could gain individual access with the same code. The only restriction they had (that I saw) was they did not have access to the eBook. They had to purchase that component. What is also nice is that after the school year, I get a new code for the following year's batch of students. The publisher rep told me that if the 45 registrations were not enough, they would send me another one for free.

    As far as using the online tool, at first I saw little to no change for the students. I mainly used it to ease my own stress with grading because I had 4 other preps at the time that required my grading attention. I liked that I could assign the homework, and leave the students responsible for keeping up with due dates and content. The second year I used it, I changed my approach: I assigned roughly 10-20 questions using MasteringPhysics and I also gave the students the solutions to correlated textbook problems. The numbers between MasteringPhysics and the textbook were different, but the problems were identical otherwise. So I figured if the students attempt their problem and struggle, they can use the solution manual as a guide in the mathematical hiccup. The real advantage was I also assigned 3-4 paper-based "Challenge Questions" to supplement the online homework. So I used the online tool to get all of the physics tools to the front of their brains, and then used the challenge problems to actually make them think. So really, the only homework that mattered was the paper-based challenge questions, but the online homework (with solutions) was a way to help keep the students grades respectable. After using this approach, I saw more 4's and 5's than I ever have before. I think the main advantage is the online homework allows us to assign the students "enough" problems that we would otherwise not assign because of the time involvement in grading.

  6. I have tested a few online physics homework systems and currently use Minds on Physics to ease my grading load and give students individualized practice. That is about $50/teacher/year. If I had a bigger budget or taught Honors/AP/IB Physics I would use the Texas Quest system.