6 ms·

How I Dealt with Student Plagiarism

112 points by reinhardt 15y ago

viraptor 15y ago
(more related to the previous post rather than this one, but still on-topic) I wonder how well would automating the process work. Right after the student clicks "submit", show the plagiarism analysis / score (previous article has a pretty interesting screenshot with all the sources annotated / issues highlighted). Would that be a sufficient deterrent? Would the guys copy/pasting the work cancel the submission if they saw that everyone will know they directly copied 60%+ of the content?
- hardy263 15y ago
  In my university programming class, we submitted assignments using turnitin, the same software you saw in the screenshot. We were allowed to see how much of our programs matched other people's programs, and where it was copied from. Scores of up to 70% were not uncommon because the whole class had the same assignment and example code to work from. The only problem is if your score was near 99%, which would probably raise some eyebrows. But since we could see what parts were considered to be plagiarized, we could easily change our program and resubmit to avoid the filter. It would only deter the students who were too lazy to change their variable names to something else.
  - Jach 15y ago
    Did anyone submit a pre-processed version of the code? (Assuming your assignments were in C.) If only one person did it they'd probably have high-uniqueness, but if >1 did it they'd all have high-sameness.
    - hardy263 15y ago
      No, it was done in C#, and even if it was in C, it's not worth the trouble to preprocess the code anyway. The assignment answers were usually simple but short. Something like sorting a linked list using insertion sort. If you have no idea how linked lists work, it's likely you would copy it. But if you understood linked lists, and already knew insertion sort, you could probably write it on the spot within 20 minutes.
      - Jach 15y ago
        Wow, so you never had to write complete programs for assignments? That "write a sort function" question seems more suitable to what I'd expect on an exam. You find out who knows/doesn't know a lot faster than a homework problem where you may be able to program it at the time but don't understand in general only to fail on the next exam, or maybe you think you know it already so you just copy from somewhere and change variables, but don't really know it, and so you also fail at test time. Bleh. The whole point of catching plagiarizers has been to determine whether work was done in some expected way, not to make sure learning happened or anything useful came from the work.
ajray 15y ago
As someone who hopes to be a future professor, posts like this are extremely valuable to me. I hope that some of the good that's come from this media storm is we'll have a surge of great ideas on how to design courses and assignments to minify plagiarizing.
- Jach 15y ago
  Is your goal to get students to understand, or get them to do the work-hours you want them to? If your course is one where a smart student could pass your exams without doing any of the assignments (or conversely an average student who might fail your exams but does well on assignments without cheating), why should you care if anyone does those assignments or even copies them? Just make assignments optional and the tests account for >90% of the grade, and use your cheating-detection skills at test-time where you can actually test understanding.
  - alf 15y ago
    The problem is that test taking is only minimally useful outside of school, and by choosing tests as the only measurement, you end up optimizing for the wrong skill. (I know because I was a pretty good test taker as a student, but the laziness and procrastination that it fosters is really starting to bite me in the ass right now) I think tests are useful because they're an easy metric, but if you're goal is to teach or learn a skill, tests are a really poor tool. As a thought experiment, if you wanted to teach yourself something what would you do? You probably wouldn't do it by giving yourself written tests.
    - equark 15y ago
      Testing can actually have a direct effect on learning: http://www.nytimes.com/2011/01/21/science/21memory.html?_r=2&ref=science http://www.nytimes.com/2011/01/21/science/21memory.html?_r=2...
      - alf 15y ago
        >A week later all four groups were given a short-answer test that assessed their ability to recall facts and draw logical conclusions based on the facts. The problem with this study is they measure learning using test. Of course the groups that had taken tests while memorizing scored better, they got practice.
varunsrin 15y ago
This brings to mind a professor at my university, who used to handout textbooks with problemsets which were most of the course's homework. The problem sets would have answers at the back, but he would misprint some of them on purpose that he could 'catch' students cheating from the back of the book. I always thought that sounded like entrapment - the assignments I tend to learn the most from are the ones that are inherently structured so that there is no way to copy / cheat on them.
- mirkules 15y ago
  This makes me wonder about the times I found problems with the answers in the back of the book. It is incredibly frustrating to work on a math problem for two or three hours, look in the back of the book to see if your answer is right, only to find it wasn't, and then to subsequently find out (from the professor) that the provided answer is wrong.
- Jach 15y ago
  That does sound awful. Especially for the students not confident in their answer, finding it's different than the back, spending time trying to get that same answer. I've had times like that where, once I got the right answer, I had convinced myself of the right way to do things and similar problems aren't as hard anymore. In the case of wrong answers, I might convince myself of something that is false. This is why I think grading on work is more important than the right answer, though of course the right answer and right work should be taken into account. If problems are such that little to no work needs to be shown, they aren't worth assignment as homework.
  - deleted 15y ago
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  - william42 15y ago
    I always hated grading on work in my earlier classes because until the work started to get challenging I could do the entire problem in my head.
joshfraser 15y ago
In the real world you don't get punished for using Google or surrounding yourself with people who are smarter than you. Maybe classroom programming shouldn't punish you either. What if you could turn in any code you wanted as long as you cited where you got it from and which license it was released under? // got this from John. he explained this to me & now I finally understand how it works! or // thanks Google! found this great code on Github (Apache 2.0 license) Of course, this approach would require assigning different types of projects than we're currently used to, but I imagine students would graduate a lot more prepared for real jobs.
- deleted 15y ago
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- shou4577 15y ago
  I think that you are right, in that this would probably prepare students for jobs very well. However, I think that a Bachelor's degree is supposed to be about something other than job training. Sure, there is some overlapping material between "prepare for a job" and "get a Bachelor's degree," but not very much. People who have a Bachelor's are expected to have knowledge that is both broad and deep. That is, they are expected to know far more than they need to know, and have skills outside of their area of expertise. Not that there is anything wrong with your approach, I just think that it disagrees with the overall goals of a standard university degree program, which is not terribly concerned about job preparation. If you can just copy and paste answers, with source, then you haven't actually learned anything (technically, you might have, but there is nothing in your work to support this conclusion - unknowledgeable until proven knowledgeable). The grade you receive should be a measure of the skills you have obtained, and the things that you have learned, rather than the results you produce. Sure, you can do this in the real world, but in the real world you are not trying to show what skills you have obtained, you are only asked to produce results - this is the major difference between the education environment and the work environment.
  - joshfraser 15y ago
    fine point
yummyfajitas 15y ago
How I dealt with student plagiarism: 10% homework 25% quizzes 25% midterm 40% final exam On rare occasions, plagiarism might have helped a borderline student move from a C+ to a B-. But I suspect it hurt more students than it helps - the plagiarism bonus on homework is usually offset by the lack of practice penalty on exams.
- cmurdock 15y ago
  This is how almost every CS and EE class was for me in college. Sure, I could have cheated on all the homework, but if I didn't understand the material, I was going to flunk the final exam. I think cheating is a bigger problem for classes with large assignments you work on outside of class and fewer exams.
- Joakal 15y ago
  I dislike quizs and exams because I view them as memorisation tests. I do badly while those people who can memorise everything so well, don't understand what they're doing. Do you allow books or computers? I'd think the internet would make it too easy as it'd allow people to communicate. Some more pet peeves: * Expected to write perfect code on paper despite students using the IDEs and documentation throughout coursework and tutorials. Professor's response "Practice writing on paper before exam/quiz" * Timed exam/quizs and it's on paper. I write far more slowly on paper than computers. In fact, I can type for many hours but after one or two hours on paper, I'm exhausted. Professor's response "Too bad / Not enough computers for everyone"
  - yummyfajitas 15y ago
    I taught math, not CS, and my exams required very little memorization. An example: http://cims.nyu.edu/~stucchio/classes/spring2009/midterm.pdf http://cims.nyu.edu/~stucchio/classes/spring2009/midterm.pdf The majority of the points are obtained via understanding. As for your experience, one can certainly come up with bad tests. Also, tests aren't perfectly fair. But overall, I'd rather penalize people for being unable to work outside their comfort zone than penalize people for not cheating.
  - 15y ago
erikb 15y ago
The idea is really nice. If I understand correctly he let's the students computer do the grading (and not the server, who he can trust a lot more), but that is just a small security design problem. Allover using a program to solve the problems of a CS class is quite smart and I wonder (since I started to study CS) why not more people do that.

112 points by reinhardt 15y ago

(more related to the previous post rather than this one, but still on-topic) I wonder how well would automating the process work. Right after the student clicks "submit", show the plagiarism analysis / score (previous article has a pretty interesting screenshot with all the sources annotated / issues highlighted). Would that be a sufficient deterrent? Would the guys copy/pasting the work cancel the submission if they saw that everyone will know they directly copied 60%+ of the content?

hardy263 15y ago
In my university programming class, we submitted assignments using turnitin, the same software you saw in the screenshot. We were allowed to see how much of our programs matched other people's programs, and where it was copied from. Scores of up to 70% were not uncommon because the whole class had the same assignment and example code to work from. The only problem is if your score was near 99%, which would probably raise some eyebrows. But since we could see what parts were considered to be plagiarized, we could easily change our program and resubmit to avoid the filter. It would only deter the students who were too lazy to change their variable names to something else.
- Jach 15y ago
  Did anyone submit a pre-processed version of the code? (Assuming your assignments were in C.) If only one person did it they'd probably have high-uniqueness, but if >1 did it they'd all have high-sameness.
  - hardy263 15y ago
    No, it was done in C#, and even if it was in C, it's not worth the trouble to preprocess the code anyway. The assignment answers were usually simple but short. Something like sorting a linked list using insertion sort. If you have no idea how linked lists work, it's likely you would copy it. But if you understood linked lists, and already knew insertion sort, you could probably write it on the spot within 20 minutes.
    - Jach 15y ago
      Wow, so you never had to write complete programs for assignments? That "write a sort function" question seems more suitable to what I'd expect on an exam. You find out who knows/doesn't know a lot faster than a homework problem where you may be able to program it at the time but don't understand in general only to fail on the next exam, or maybe you think you know it already so you just copy from somewhere and change variables, but don't really know it, and so you also fail at test time. Bleh. The whole point of catching plagiarizers has been to determine whether work was done in some expected way, not to make sure learning happened or anything useful came from the work.

ajray 15y ago

As someone who hopes to be a future professor, posts like this are extremely valuable to me. I hope that some of the good that's come from this media storm is we'll have a surge of great ideas on how to design courses and assignments to minify plagiarizing.

Jach 15y ago
Is your goal to get students to understand, or get them to do the work-hours you want them to? If your course is one where a smart student could pass your exams without doing any of the assignments (or conversely an average student who might fail your exams but does well on assignments without cheating), why should you care if anyone does those assignments or even copies them? Just make assignments optional and the tests account for >90% of the grade, and use your cheating-detection skills at test-time where you can actually test understanding.
- alf 15y ago
  The problem is that test taking is only minimally useful outside of school, and by choosing tests as the only measurement, you end up optimizing for the wrong skill. (I know because I was a pretty good test taker as a student, but the laziness and procrastination that it fosters is really starting to bite me in the ass right now) I think tests are useful because they're an easy metric, but if you're goal is to teach or learn a skill, tests are a really poor tool. As a thought experiment, if you wanted to teach yourself something what would you do? You probably wouldn't do it by giving yourself written tests.
  - equark 15y ago
    Testing can actually have a direct effect on learning: http://www.nytimes.com/2011/01/21/science/21memory.html?_r=2&ref=science http://www.nytimes.com/2011/01/21/science/21memory.html?_r=2...
    - alf 15y ago
      >A week later all four groups were given a short-answer test that assessed their ability to recall facts and draw logical conclusions based on the facts. The problem with this study is they measure learning using test. Of course the groups that had taken tests while memorizing scored better, they got practice.

varunsrin 15y ago

This brings to mind a professor at my university, who used to handout textbooks with problemsets which were most of the course's homework. The problem sets would have answers at the back, but he would misprint some of them on purpose that he could 'catch' students cheating from the back of the book. I always thought that sounded like entrapment - the assignments I tend to learn the most from are the ones that are inherently structured so that there is no way to copy / cheat on them.

mirkules 15y ago
This makes me wonder about the times I found problems with the answers in the back of the book. It is incredibly frustrating to work on a math problem for two or three hours, look in the back of the book to see if your answer is right, only to find it wasn't, and then to subsequently find out (from the professor) that the provided answer is wrong.
Jach 15y ago
That does sound awful. Especially for the students not confident in their answer, finding it's different than the back, spending time trying to get that same answer. I've had times like that where, once I got the right answer, I had convinced myself of the right way to do things and similar problems aren't as hard anymore. In the case of wrong answers, I might convince myself of something that is false. This is why I think grading on work is more important than the right answer, though of course the right answer and right work should be taken into account. If problems are such that little to no work needs to be shown, they aren't worth assignment as homework.
- deleted 15y ago
  [deleted]
- deleted 15y ago
  [deleted]
- william42 15y ago
  I always hated grading on work in my earlier classes because until the work started to get challenging I could do the entire problem in my head.

joshfraser 15y ago

In the real world you don't get punished for using Google or surrounding yourself with people who are smarter than you. Maybe classroom programming shouldn't punish you either. What if you could turn in any code you wanted as long as you cited where you got it from and which license it was released under? // got this from John. he explained this to me & now I finally understand how it works! or // thanks Google! found this great code on Github (Apache 2.0 license) Of course, this approach would require assigning different types of projects than we're currently used to, but I imagine students would graduate a lot more prepared for real jobs.

deleted 15y ago
[deleted]
shou4577 15y ago
I think that you are right, in that this would probably prepare students for jobs very well. However, I think that a Bachelor's degree is supposed to be about something other than job training. Sure, there is some overlapping material between "prepare for a job" and "get a Bachelor's degree," but not very much. People who have a Bachelor's are expected to have knowledge that is both broad and deep. That is, they are expected to know far more than they need to know, and have skills outside of their area of expertise. Not that there is anything wrong with your approach, I just think that it disagrees with the overall goals of a standard university degree program, which is not terribly concerned about job preparation. If you can just copy and paste answers, with source, then you haven't actually learned anything (technically, you might have, but there is nothing in your work to support this conclusion - unknowledgeable until proven knowledgeable). The grade you receive should be a measure of the skills you have obtained, and the things that you have learned, rather than the results you produce. Sure, you can do this in the real world, but in the real world you are not trying to show what skills you have obtained, you are only asked to produce results - this is the major difference between the education environment and the work environment.
- joshfraser 15y ago
  fine point

yummyfajitas 15y ago

How I dealt with student plagiarism: 10% homework 25% quizzes 25% midterm 40% final exam On rare occasions, plagiarism might have helped a borderline student move from a C+ to a B-. But I suspect it hurt more students than it helps - the plagiarism bonus on homework is usually offset by the lack of practice penalty on exams.

cmurdock 15y ago
This is how almost every CS and EE class was for me in college. Sure, I could have cheated on all the homework, but if I didn't understand the material, I was going to flunk the final exam. I think cheating is a bigger problem for classes with large assignments you work on outside of class and fewer exams.
Joakal 15y ago
I dislike quizs and exams because I view them as memorisation tests. I do badly while those people who can memorise everything so well, don't understand what they're doing. Do you allow books or computers? I'd think the internet would make it too easy as it'd allow people to communicate. Some more pet peeves: * Expected to write perfect code on paper despite students using the IDEs and documentation throughout coursework and tutorials. Professor's response "Practice writing on paper before exam/quiz" * Timed exam/quizs and it's on paper. I write far more slowly on paper than computers. In fact, I can type for many hours but after one or two hours on paper, I'm exhausted. Professor's response "Too bad / Not enough computers for everyone"
- yummyfajitas 15y ago
  I taught math, not CS, and my exams required very little memorization. An example: http://cims.nyu.edu/~stucchio/classes/spring2009/midterm.pdf http://cims.nyu.edu/~stucchio/classes/spring2009/midterm.pdf The majority of the points are obtained via understanding. As for your experience, one can certainly come up with bad tests. Also, tests aren't perfectly fair. But overall, I'd rather penalize people for being unable to work outside their comfort zone than penalize people for not cheating.
- 15y ago

erikb 15y ago

The idea is really nice. If I understand correctly he let's the students computer do the grading (and not the server, who he can trust a lot more), but that is just a small security design problem. Allover using a program to solve the problems of a CS class is quite smart and I wonder (since I started to study CS) why not more people do that.