Should I prepare new homework exercises each year, 20% of the final grade is homework?

Question

This year I prepare a new course (in programming, but it could be any other course). I spend a lot of effort in creating homework exercises. This is fun, but also very time-consuming.

I wonder if I can use the same exercises next year, when I teach this course again. The main problem is that, once the solutions are out, surely some students next year will be able to get them and copy them. It may be possible to use some automatic plagiarism detection tools, but it is quite difficult and not very reliable.

I believe the copiers will not gain much from copying, since the homework grade is only 20% of the final grade. On the contrary, they will lose since they will be less prepared for the exam, which is 80% of the final grade. My fear is that the temptation to copy will harm these students. So maybe I should create new exercises to avoid the temptation to copy.

On the other hand, the students are grown-ups, if they choose to copy, it is their problem and they should bear the consequences of not knowing the material well enough. Should I work so hard each year, only to protect the copiers from their own faults?

Answer 1

The main dilemma is that the homework is part of the grades, therefore you should prepare a new one each semester.

I solved this for my programming course in a radical way (after struggling with a similar issue for a few years): I made all homework optional, and only the exams count. I make it very clear that the students will fail if they don't do the exercises (and some prove me right each year which is motivating for the others). Students are getting feedback on their submissions and they can even submit revisions. I'm using the homework results (anonymously) for the course where I'm discussing common errors and best practices.

What I did instead is to build dependencies in our course management website (in our case Moodle based): The students only get access to the next chapters if they at least submit the mandatory (minimum) exercises. Yes, they can submit crap, but it's hard to evaluate each submission in very little time so I'm willing to accept this loophole, and at least up until now, students haven't used this option.

The second thing I do is have three live programming sessions where the students have to solve little tasks (in general quite simple exercises) without an internet connection. You have to pass all three of them. Since this happens during the semester, they recieve a feedback about their progress quite early. Each test can be repeated once during the semester.

The combination of thoses measures results in high participation rates and people have no more motivation to copy solutions since they don't have any benefit from it.

Answer 2

It is useful to have a pool of questions to avoid having the same questions every year. If you have questions for like 2,5 years, you are able to mix them in every year and it is hard to use the previous years notes of somebody else to copy the answers.

If you do not have enough questions yet, you can try changing some numbers and variable names at least, so simple copying will be noticed. Of course you still need to check afterwards if the new questions and answers are correct, but you will still be faster than when writing new ones.

If the homework is graded in the final grade of the course, you cannot tolerate copying. If it is only needed for admission to the exam, it does not matter. People are grown up and if they want to be admitted without being prepared that's their problem.

Answer 3

There is always a trade-off. While it would be really nice to have new exercises each year, you need to ask yourself if your time would not be spend better someplace else, for example in better preparing other parts of the course. Additionally old exercises have the benefit that you can learn from your mistakes. In my experience, each semester there are a few exercises which I thought were easy and straightforward but which were really problematic for the students. Furthermore I am much more incentivised to create good and comprehensive solutions for myself (and possibly the TAs), if I am most likely going to use them several times in a row. Finally there are also some exercises which are kind of mandatory and do not really have an alternative, usually the more theoretic ones.

That does not mean that you should not prepare some new exercises. Usually you get some new ideas throughout the year and personally I try to make a habit of noting them down for possible later use. On the other hand there are always some exercises that did not quite work as intended and can't really be fixed or which become obsolete due to slight changes in the course material or its order.

So in other words, this is not a binary problem, the middle ground of changing only some of the exercises is quite valid too.

If you are worried about plagiarism, often there are also some quick changes that can be done without much work, such as changing some numbers and descriptions, as well as the text of the exercise and its formatting. While it will not fool everybody it at least requires students to recognize that the problem is isomorphic to an old one and enough understanding of the old solution to see where changes need to be made. Of course this does only work if you hide it in real changes, that is add in some new exercise and tweak their order, otherwise it will be too obvious.

As a final idea, you could even outsource things a bit. This will not work for every course but should be fine for a programming course. Near the end of the course, as an optional additional exercise problem, ask them to design their own exercise on one of the topics of the course, including a short description of why said exercise will be helpful in understanding a certain topic. If you offer some prizes such as a bottle of wine (if your students are allowed to drink) and some chocolate for the runner ups, you might get some good new ideas for next year.

Answer 4

It depends what you think the role of University is. For me, it remains an institution dedicated to learning and understanding. Grades are important for employment but ultimately, University should give those that want to learn an opportunity to learn.

Do new questions enhance the learning experience? Possibly yes, if the old questions and solutions are available to the students, then they can use it to help them learn how to approche such problems.

At the same time, if the old questions were good enough to help students learn last year, then they are good enough to help students learn this year.

I do not think that it is the role of the university to enforce disciplin for students that do not want to learn. There are a myriade ways to cheat, I think it is sufficient to remove solutions for the problems at the beginning of the year.

Answer 5

I believe it is worth your effort to create different (or even just slightly different) sets of assignments every time you teach a course. I believe it gives current students an incentive to solve the assignment without copying from others. If you give the same assignment every time, then even the best students may be tempted to just copy the solutions obtained from previous students.

To make it more difficult for students to copy from each other, I usually have at least two sets of assignments (call them sets A and B) and I take note of which set was given to which student. This makes it difficult for students to copy from others in the present. Then the next time I teach the course, I try to create two new sets (C and D). This makes it difficult to copy from others in the past. (If you don't have the time to create totally new sets, then just make some small changes.)

Answer 6

Student perspective here.

By all means. Repeating the same graded exercises (this includes exams) year by year is extremely demotivating for the student effectively discouraging learning process by putting students in the position when they choose between:

• Learning and academic integrity where they work hard with possibility of failure.
• Plagiarism or memoising known correct answers with guaranteed success.

At least in a short term this is gives a serious advantage to dishonest agents, and is extremely frustrating.

Answer 7

From my experience as a student. I would say that you should have a 2/3 year cycle where you repeat the question. Some lecturers in my university did the same assignment every year and most students had a connections with the students the year above and were able to obtain the answer easily and cheat.

The 2/3 year repetition cycle would allow you to built in depth answers as well as solve any little problems (i.e. too difficult/easy) in the questions whilst the reducing the chances of student obtaining the answers from the previous students.

Edit 1.

The idea one lecturer used was to repeat the same questions every year however he would very slightly tweak the numbers which caught some cheating students who obtained answers from previous students but forgot to change the numbers.

Answer 8

I think that making new sets of questions is not necessary, and having same assignments can actually be beneficial for students. If they get stuck on something they can look at the solution, even one line can make everything click, be it in math, programming, physics etc.

You already said, that the students are grown ups, and choosing to copy will only be detrimental to their understanding, so the serious students, who look to understand the subject better, not just get a passing grade, will still do the assignments by themselves.

You also specified that you teach a course in programming, so you have an advantage - when students hand in their assignments you can ask them to make a simple modification in their software, but one that requires them to understand what is written. At least that is how it works in my university, where modification is 40% of the grade from the assignment. An example modification, just as I was doing last week would be: Assigned software gives solutions to a 3x3 system of equations, make it work for 5x5 system.

That is just the perspective from a view of a student, so all in all if I were teaching a course, I wouldn't change them.

Answer 9

No. I recommend that you do not spend the time making new programming homework every year.

Consider that as a tenure-rack academic (U.S. perspective here), you will be rewarded and promoted based on published research, not on teaching effort. It's self-destructive to not take those goalposts into account; you should be prioritizing and rationalizing your time spent on teaching appropriately. This particular task can take an extremely large amount of time (creatively designing new tasks, creating new grading rubrics, re-inventing the knowledge of where the tricky spots are, every cycle, etc.), and there isn't a very great advantage in educational outcomes.

For the cheating issue, I have been very happy using the free Moss (Aiken, Stanford U.) code plagiarism checker. What is highly educational, and gets very rapid student attention, is to have a clear first-day discussion of plagiarism principles and then hand out several zeroes on the first assignment or two for those who violate them. In that sense, confronting them with the opportunity/temptation to plagiarize and correcting for that is itself a more salutary lesson than the rest of the assignment.

But in short: The priority is your limited time. The payoff for the time making new exercises year is woefully insufficient.

Answer 10

Creating new assignments every year does not prevent students from copying solutions from fellow students in the same semester, which imho is just as big of a problem. From my own experience this was rampant in my courses where something had to be submitted as a solution to very specific tasks.

Students would come up to you and just ask "Hey, did you already finish this task? Could you send me your solution for inspiration purposes." It is usually hard to decline this kind of request if you are friends with these people. Some really only use it as a help if they are stuck but some just change variable names and the "worst" submit a verbatim copy.

Therefore you should focus on making sure students actually solved a specific homework regardless of when it was created.

I see three possible solutions:

1. Make the content of the homework highly relevant to the exam.

I had several assignments where e.g. I would have to create a small software project and spent nearly a week finishing it. Then in the exam, there were only few questions about very basic stuff that you could have gotten from reading 2-3 slides. This would be OK if all students were honest and everyone would have dealt with the subject already so you could skip it in the exam. But because many weren't it was very frustrating for me who actually did spend one week on it and then in the exam there was no reward for having done everything myself. This decreased my motivation to do things properly next time. All the work felt wasted. If you work hard, you want to get some kind of appreciation grade wise.

So make as much of the final exam about subjects covered in homework. Then people will feel the need to actually study it and "the good" students will feel like it was worth investing this much time.

1.1. This is also solves the same problem for group projects

The majority of many group assignments are done by a minority, i.e. the one most motivated student. It was my experience that a lot of my group work ended with me doing most of the work but the others still got the same grade.

If the homework is very relevant to the exam, they will be penalized then. And again the one who put in all the work will feel rewarded.

2. Be specific in the requirements but vague in the implementation

As @WGroleau already wrote, make the task description specific in the requirements but very open in the implementation. This will lead to more individual solutions and plagiarism will be easier to detect.

3. Let students present their solution individually for 5-10 minutes.

If someone submits a solution but can not explain a simple loop or why certain methods are called or what they are doing, you will be able to filter out cheaters quickly.

Caveat from personal experience: Sometimes the presentation was a week or two after the submission so when it came to presenting it, I had forgotten some things, and was struggling to explain basic things in the first few minutes. This was because I did not prepare for the presentation thinking I could do it on-the-fly. A hint to students to prepare might alleviate this.

Answer 11

I always try to prepare a new set of homework questions -- regardless of the percentage.

As you have mentioned, there will always be a subset of students who will copy their way out, no matter how original your questions are. But there are also students who do not copy, and put their effort to solve the questions. They take the course seriously, they do not try to reach the ones from previous years.
So, I feel like should respect them and bring out a set of new questions.

Answer 12

Although you said “any other course,” my answer just applies to your programming situation:

Specify the requirements at a high enough level that a good solution requires declaring/defining additional variables, data types, subprograms, etc. Then plagiarism will be obvious (unless the cheater carefully goes through the code changing all the identifiers).

Answer 13

There's an extent to which there's nothing you can do about this. Presumably you're not going to get a new textbook every year. You said this is a programming class: I don't suppose you're going to switch to a different language every year. Etc.

I think a system many teachers use for tests is to build up a body of questions, and then use a different subset in a different order every year. Like one year ask questions A, B, C, D, and E. The next year ask D, B, F, G, and A, etc.

You could do something similar for homework. Have a set of problems and shuffle them around.

For a programming class, I think an easy solution would be to alter the problem just slightly every year. Life if one year a programming assignment is "read in two numbers, add them together, and display the result", (presumably a very early assignment!) maybe the next year it's "multiply them", and the next year it's "add them together and add 2". The suspicious part of me notes that this could make it easy to catch the very lazy cheaters. If this year's problem looks very much like last year's problem and just has a couple of words different, then if someone turns in an assignment that solves last year's problem rather than this year's, good chance he copied it from another student.

For any non-trivial problem, the chance that two programmers will come up with identical solutions is small, but I suppose checking for that would require keeping a database of every homework assignment ever turned in. And many cheaters are smart enough to change a few things around so it's not identical.

Answer 14

The Stack Exchange volunteers' perspective.

You have in other answers the perspective of other academics, and the perspective of students. Now have the perspective of wholly third parties not at your institutions that are nonetheless involved in this because your students are coming to us.

We get the fallout from this here at Stack Exchange. For some several years now volunteers like me have been spotting computer science/programming coursework problems that students take and simply re-post to Stack Exchange, to get people from around the world to solve for them for free. They aren't copying prior answers.

From this perspective:

• Hiding coursework questions behind a kind of adventure game interface, where they are not visible except to people who have completed a quest (i.e. handed in the preceding coursework), does not help us volunteers. It actively thwarts us, as we rely on the questions being public in order to find whose course work, at what institution, they come from. The same goes for restricting WWW spiders from crawling the questions.
• Varying coursework from year to year does not address the problem. Students just submit this year's variant to Stack Exchange, and some eager volunteer happily swoops in to do someone else's school or university coursework afresh.
• Slight variations, enough to make the answer different whilst still triggering memories of years gone past, are better than drastic variations for us. We volunteers only have pattern recognition for your chosen example names and scenarios, and seasonal memories such as Oh, is it the end of the Epiphany Term again so soon?, to go on.
• A hyperlink to your institution's academic honesty policy that is direct (e.g. no Word documents), stable in the long term, and specific (i.e. your policy should not be tens of paragraphs down a single page containing lots of policies without an anchor for its specific section heading), is a useful thing.

  Also note that people will read "archived" as "no longer applies". That's not a useful way to present a current policy, either.

In a sense, you are committing the same error as military organizations do of preparing to fight the last war rather than the next one. The students of the world have already, years ago, worked around the detection of copied answers. They nowadays use WWW sites including the very family of Q&A sites that you are asking this on to get eager people, from potentially multiple far away countries, without pay or indeed any connection to the students or to you, to solve their year-to-year different coursework problems for them.

Further reading

From my own direct experience, and I am just one volunteer who can only recognize a limited number of patterns.

• ULI101/UNX101
  • https://ca.answers.yahoo.com/question/index?qid=20130208180515AAV778P
  • https://unix.stackexchange.com/questions/168076/unix-grep-confusion#comment558984_168076
  • https://unix.stackexchange.com/questions/164762/remove-parent-and-sub-directory/164764#comment558985_164762
  • https://unix.stackexchange.com/questions/162354/how-can-i-copy-a-file-from-another-directory-to-the-current-one#comment558983_162354
  • https://unix.stackexchange.com/questions/353471/linux-unix-tree-diagram/353478#comment626268_353471
  • https://unix.stackexchange.com/questions/209262/what-command-would-i-issue-in-order-to-complete-this-question#comment353747_209262
  • https://superuser.com/questions/996053/
  • https://unix.stackexchange.com/questions/318075/
  • https://unix.stackexchange.com/questions/317816/
  • https://unix.stackexchange.com/questions/211656/
  • https://stackoverflow.com/questions/19193933/
  • https://stackoverflow.com/questions/45194004/
• CSCI132
  • https://unix.stackexchange.com/questions/396925/
  • https://unix.stackexchange.com/questions/396574/
  • https://unix.stackexchange.com/questions/396912/
  • https://stackoverflow.com/questions/46739658/
• Meta
  • https://unix.meta.stackexchange.com/questions/4206/

Answer 15

Do you change how you teach the class based on how it goes each year? Unless you're a veteran professor, you should be doing this. So your homework questions will naturally change.

Putting that aside: Make two years worth of different questions, and then alternate every year you teach the class. Most students don't know classmates 2 years ahead of them, making it hard for them to cheat.

So if you teach the class 2 semesters per year, 4 "full sets" would prevent the vast majority of cheating.

Answer 16

Failure to create new material each year is the reason fraternities and sororities in the US gather homework and test banks.

Professors give an advantage to students who are members of any organizations that may use such tactics if they don’t make new homework and new exams.

https://www.reddit.com/r/GreekLife/comments/2hiz1p/how_is_your_organiations_test_bank_run/