Dot Physics

I am pretty sure this came up on some email discussion listserv. Someone mentioned that students could just look up the answers to homework on Maybe you are more with it than I am, but I had never heard of this. Of course I had to check it out.

At the basic level, cramster gives solutions to homework problems. I was surprised how many introductory physics texts were available. They even had Classical Electrodynamics by Jackson. They did not have the text I use for calc-based intro physics, Matter and Interactions.

So, I tried it out. The site is pretty nice. They have tons of solutions. It seems to be that you can ask and access answers based on karma (by answering other questions) or by paying more. That is really just a guess though. The site also has a general question and answer forum type area. Even though says “just help, don’t give the answer” typically the answer is given.

Then what is the problem? The problem is with my jobs. Yes, jobs. I have two jobs. My first job is to help students learn. I am a learning-faciliator if you like. I do this in many different ways. One way is to assign homework. Oh, my other job is to evaluate how well students understand the material. I have to give them some grade at the end of the semester. One obvious way to do this is with an exam or feats of strength.

Here is the question: Do you grade homework? Oh, I know what everyone says. If you don’t give a grade for the homework, they won’t do it. But I think if it is worth a grade, they will try to get a grade, and not try to learn. Clearly, it is easy to get solutions off the internets. Yes, I know there are other strategies to prevent them from cheating. But I say, why? Why prevent them from helping themselves?

Suppose I were not a learning-facilitor but a trainer at the gym. Would I pay people to do their exercises?

Ok. Maybe you could consider the homework as part of your evaluation of their understanding. Sort of like take home quizzes. But if you do that, then you are going to have to deal with stuff like

I admit, I have given grades for homework. It is hard to say it is not graded (well, I do collect homework and give feedback – or have WebAssign do that). But when it becomes clear that the homework is for THEM, it is easier to use it as a learning tool (which is what it is).


  1. #1 Kevin Sooley
    July 23, 2009

    Suppose I were not a learning-facilitor but a trainer at the gym. Would I pay people to do their exercises?

    That’s not that good an analogy. If you can’t do an exercise, you can leave it and try again in a week. If you don’t understand your homework, you’re going to get it wrong.

  2. #2 Rhett
    July 23, 2009


    Damn. I knew that wasn’t going to work when I wrote it and then I thought….oh well. Grades are not like paying.

    Although with homework, I let students resubmit as much as they like.

  3. #3 Carleigh
    July 23, 2009

    Hi Rhett,

    I like this post. Rather than outlawing them, I tend to think that educators should spend more time focusing on the effective and responsible use of the various resources (online and off) that are available to students. Students will quickly realize: sure, you can get help on your homework, but make sure the help you are getting is of the highest quality so that, come test day when resources are not available, you are ready.

    In a May 17 NYT article about study sites, one educator was quoted as saying “As faculty, we need to be better educated about what the possibilities are, and the truth is you can’t put the genie back in the bottle… If Cramster and all these companies disappeared tomorrow, you could still do a Google search and find what you’re looking for in five minutes.” I agree– this is they way of the world now.

    If homework wasn’t graded at all, the emphasis may be more easily placed on the student’s responsibility not to get a good grade, but to learn.

    Carleigh McKenna

    By the way– I’d love to give you a more in-depth tour of the site! Let me know if you’d like more info.

  4. #4 Anonymous Coward
    July 23, 2009

    To answer the question: I grade homeworks.

    The homeworks count for a significant portion of the students’ grades. Thanks to Cramster (or other sources?) I no longer assign problems from the book – it was obvious multiple students were copying from solution sets – so I’ve taken to writing up my own homeworks. After grading them, I give them back to the students with solution sets I’ve written.

    There are a lot of negatives to this: it’s significantly more work for me, and the homework sets I give them are probably inferior to the ones from the book*. On the other hand, I think the students appreciate it (because they all know about Cramster) and it helps engender a bit of respect because they know I’m putting in the extra effort. But I’d go back to problems from the book in a heartbeat if I was confident they wouldn’t just copy the solution sets.

    *On the other hand, the problems I give may be more “realistic” examples of doing physics, as they are often more complicated than expected, and (unintentionally) often have open answers.

  5. #5 Al
    July 23, 2009

    I am a high school physics teacher and I too assign and grade homework I make. It is more work for me, especially if I know I have students that merely copy the solutions from their friends. My students are encouraged to work together on their homework, the good students and the weak ones too seem to benefit from it.

    I need to know if the students are grasping concepts or just muddling through, and homework is the fastest way to get feedback. We have standardized tests at the end of the semester and the students desrve a fighting chance to do well.

  6. #6 Lori
    July 24, 2009

    I am also a high school physics teacher. I use WebAssign for homework, but I can’t justify counting it for a large portion of the grade because of factors like cramster etc. What bothers me is that the students with more financial resources will have an advantage of those that do not. Cramster is not completely free. My district also has a policy that homework can only count 10%. But I like to give in class quizzes on homework questions to assess who actually understood the homework.

  7. #7 Alex
    July 24, 2009

    I grade homework in my physical science course. A majority of the homework I write myself but I also take some problems from our unofficial textbook Conceptual Physics. I do not indicate to students which problems I’ve written and which problems I’ve taken from the textbook so I’m not worried about students trying to find the answers online. Students never know what’s from a textbook or even if they try they don’t have chapter or problem numbers to search for.

    I tend to have fairly short (10 problems or less) homework assignments which I count as a big portion of the semester grade. This is mainly because this is what I’m used to in classes I take a graduate student. I plan to shift the grade emphasis more towards labs/activities than homework. Not because of online homework resources but because what will be of use to students after they finish my class are the process’s and reasoning they learn in labs not using Fnet=ma to solve for an object’s acceleration.

  8. #8 Kevin Sooley
    July 24, 2009


    Oh! That makes it a fair bit better.

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