difficulty grading exams marked on an ipad

Added by S. McKay about 8 years ago

Hi,
I hope that I'm not asking a question that has been asked many times already ...

I have some python code that helps me to grade exams on an ipad (or other tablet - ipad is what I'm familiar with). I was hoping to use AMC to record grades. However, I am running into difficulties. After the student has marked the exam (including any multiple choice questions), I put the exam on the ipad and grade the open questions, and assign a mark by checking one of the boxes from AMCOpen. I then transfer the file to dropbox, where I massage it some more. (Mainly putting exams back together, as my program gives me one file for each page of the exam). At this point, I flatten the pdf (on a mac). The marks I made are still clearly visible. I then run AMC (on an ubuntu server). AMC seems to run correctly when I mark and annotate the papers, but when I look at the papers, the grader marks that I gave it on the ipad are now missing. So, something is happening, probably when the pdf is being converted (to tiff?). As far as I know, once the pdf has been flattened, there should be no way to tell where the marks came from. So I am unsure what is happening here.

I have just run this on a test, so the number of pages per exam is one. Is there a setting I could tweak? Is something else going on?

Any help would be appreciated. I am attaching the (graded) pdf file so you can look at it.

Thanks


Replies (5)

RE: difficulty grading exams marked on an ipad - Added by Alexis Bienvenüe about 8 years ago

AMC first tries to extract the scan from the PDF file with pdfimages. If your PDF contains one image for the scan and a small image (or vector graphics) for your drawings, only the first will be used.
You can tick Edit/Preferences/Scan/Scan conversion/Force conversion to tell AMC not to use pdfimages, but a PDF→RASTER converter.
You can also consider marking your open questions from the Data capture/Manual window, selecting Scan as the background, instead of Original.

RE: difficulty grading exams marked on an ipad - Added by S. McKay about 8 years ago

Hm. That did not work. selecting that option does not seem to change the outcome. By the way, when I change a preference, it seems that I have to restart AMC before the preference is honored...

This is what worked. I used convert (from imagemagik) to convert the pdf to jpg, and then converted the jpg back to pdf. Then, when I run AMC on the file (with or without the box being checked), then it works - the checkmarks remain in place, and are graded correctly.

So, for now I have a workaround, but I would really like to know why this is happening, so I can find a better solution ...

I do not want to use manual data capture, because I plan to use this for commonly graded exams with many graders and 500-1000 students ...

Thanks,
S.M.

RE: difficulty grading exams marked on an ipad - Added by Alexis Bienvenüe about 8 years ago

and then converted the jpg back to pdf

This should not be necessary: AMC can handle JPG files.

RE: difficulty grading exams marked on an ipad - Added by Alexis Bienvenüe about 8 years ago

selecting that option does not seem to change the outcome

Yes, this is a bug. I corrected this in hg:b3e7eed19206. This is just a line to add to AMC-getimages.pl, you can add it yourself to test.

RE: difficulty grading exams marked on an ipad - Added by S. McKay about 8 years ago

Thanks for your help. I am about ready for my first trial of this system. I am hoping that it will help to speed up the hand grading of many exams.

(1-5/5)