Investigating suspected plagiarism

One of our students just submitted a project (TEALS Intro to CS Unit 6) that the teacher (I'm one of the TAs) suspects has been plagiarized. Any ideas how to search for a comparable program on the Web? I checked here:, but didn't see any immediately obvious similarities, and I won't do a manual search of 3,662 published projects.



P.S. Here's my copy of the project:

Why does the teacher believe it is plagiarized? Can the student no explain the code, or is it similar to another student's work?

Too advanced. (It is not similar to any other submitted work this semester.) It's as though a student who had been struggling with long division suddenly turned in a breakthrough scientific paper on quantum gravity. (I'm exaggerating, but you get the idea.) There is a body of work for each student, stretching over an entire semester, and this student hasn't written anything anywhere near as advanced before.

The teacher hasn't had time to have the student explain the code to her.

If one could get a database of all published project's XML files, it might be possible to use a system compares your project to every other one.

You may custom search. @bh or @jens may know about it.

How? Where? I would need to search inside the program for a match. If it was taken from a prior work, the name has been changed.

I can't understand what are you saying.

You said: "You may custom search." I am asking you how to do that. I have no idea.

Well, you may use Google Custom Search.

Talk to the student and see if they can explain it, the code still seems pretty basic and it could be that they have just been playing around with Snap!

That might be a good idea, but he or she, i.e. they may lie.

Is the project a game?

Found it. He got it from Scratch, and then ported it to Snap!


Did he make it by his own on Scratch?

No, he did not.

Okay. That's bad though. Have a great day! Merry Christmas!

To add some context, and answer this for any related questions:

We do not have an easy way to search the contents of projects, only names and descriptions. Naturally, it's possible, but requires a significant amount of effort we cannot support.

The search box only searches published stuff, and there's still relatively few published projects. Projects that are "shared" (meaning via a link only) will not show via searching.
It's not terribly hard to translate a Scratch project into Snap!, and so far this has been the vast majority of copying we've seen or had reported to us.