3 ms·

> FFS how many different implementations of quicksort in Python can there possibly be? How would they expect you to make yours unique? Different variable names

by msla 8y ago

> FFS how many different implementations of quicksort in Python can there possibly be? How would they expect you to make yours unique? Different variable names or something? Not even different variable names, as any plagiarism detector which is halfway-competent would have to ignore them because changing variable names is one of the things any halfway-competent plagiarist would do. The arms race has gone to the point where it's impossible to detect mechanically whether an implementation of a standard algorithm has been plagiarized. It's probably impossible for a human to detect it without other context. And that context comes down to "Has this student shown steady gains or are they suddenly handing in competent code after demonstrating complete incompetence?" which you can't know unless the class is structured such that students show what they know to the graders in person. Which requires a certain student-to-grader ratio. Which is expensive.

zrobotics 8y ago
The problem is, it isn't at all unlikely that a quicksort implementation created entirely independently w/o plagiarizing will match an implementation somewhere online. When I took algorithms, I would normally do the assignment and compare my implementation with online sources, mostly to compare against. Aside from variable names, ~80% of those assignments matched one of the first few SO answers. I think the real fail here is a company assigning something like quicksort and expecting to get original answers.
- msla 8y ago
  > The problem is, it isn't at all unlikely that a quicksort implementation created entirely independently w/o plagiarizing will match an implementation somewhere online. It's practically guaranteed. Quicksort is quicksort. You can't get creative with it without implementing something which isn't quicksort anymore. That code may well sort a list, but if the assignment is to implement quicksort, you've failed at the task. > I think the real fail here is a company assigning something like quicksort and expecting to get original answers. Right. You have to go to IOCCC levels of perversity to be able to turn in something which is quicksort but isn't going to trip a well-trained plagiarism detector.
  - hermitdev 8y ago
    I remember being asked how I'd go about implementing quicksort in a phone interview. My response was: I wouldn't. Sorting is a solved problem that's available in pretty much any language's standard library (every non assembly language I've used, at least). The interviewer chuckled and something to the effect of "good answer, then can you describe the algorithm to me?", to which I said sure, and did. Thankfully, I went through college before these automated plagiarism detectors had caught on. They were around, but not as pervasive as today. I mean, if you're going to sort a vector in C++ for a trivial app, there's only so many ways to write: std::vector<int> stuff{...}; std::sort(std::begin(stuff), std::end(stuff)); And, lets face it: most lab assignments requiring a student to write a program are pretty small and trivial (at least mine were 20 years ago). The projects, on the other hand, were definitely more involved and you'd likely see more divergence in solutions there.

by msla 8y ago

zrobotics 8y ago

The problem is, it isn't at all unlikely that a quicksort implementation created entirely independently w/o plagiarizing will match an implementation somewhere online. When I took algorithms, I would normally do the assignment and compare my implementation with online sources, mostly to compare against. Aside from variable names, ~80% of those assignments matched one of the first few SO answers. I think the real fail here is a company assigning something like quicksort and expecting to get original answers.

msla 8y ago
> The problem is, it isn't at all unlikely that a quicksort implementation created entirely independently w/o plagiarizing will match an implementation somewhere online. It's practically guaranteed. Quicksort is quicksort. You can't get creative with it without implementing something which isn't quicksort anymore. That code may well sort a list, but if the assignment is to implement quicksort, you've failed at the task. > I think the real fail here is a company assigning something like quicksort and expecting to get original answers. Right. You have to go to IOCCC levels of perversity to be able to turn in something which is quicksort but isn't going to trip a well-trained plagiarism detector.
- hermitdev 8y ago
  I remember being asked how I'd go about implementing quicksort in a phone interview. My response was: I wouldn't. Sorting is a solved problem that's available in pretty much any language's standard library (every non assembly language I've used, at least). The interviewer chuckled and something to the effect of "good answer, then can you describe the algorithm to me?", to which I said sure, and did. Thankfully, I went through college before these automated plagiarism detectors had caught on. They were around, but not as pervasive as today. I mean, if you're going to sort a vector in C++ for a trivial app, there's only so many ways to write: std::vector<int> stuff{...}; std::sort(std::begin(stuff), std::end(stuff)); And, lets face it: most lab assignments requiring a student to write a program are pretty small and trivial (at least mine were 20 years ago). The projects, on the other hand, were definitely more involved and you'd likely see more divergence in solutions there.