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Automatically grading multiple choice exams from photos using Python and OpenCV
- epalmer 10y agoThis is pretty cool. I am getting ready to embark on camera projects with a Raspberry Pi 3 and saw this project. Since I will be using python and OpenCV anyway this is a motivator.
- zionsrogue 10y agoCombining the Raspberry Pi + Python + OpenCV is a lot of fun. If you feel like sharing the details on your project I might be able to point you in the right direction.
- epalmer 10y agoSend me an email and let me know what you had in mind. epalmer _at_ richmond _dot_ edu
- epalmer 10y agoYou wrote the ebook right? I think I'll get it.
- zionsrogue 10y agoCorrect, I am the author of Practical Python and OpenCV.
- mandudebruh 10y agoHere's a similar service: http://bubblevision.org/ http://bubblevision.org/
- andersonfreitas 10y agoAn open source alternative: http://www.formscanner.org/ http://www.formscanner.org/
- honkhonkpants 10y agoIf only I had Adobe Flash, I could learn all about this!
- dylz 10y agoVLC -> open network -> http://embed.wistia.com/deliveries/5bed39f586d77c4436f569d164e910dbe75eb739.bin http://embed.wistia.com/deliveries/5bed39f586d77c4436f569d16... if you actually want to
- coredog64 10y agoThe author has been pretty good at documenting a number of simple projects that can start you off in OpenCV. Disclaimer: I bought his eBook bundle.
- mountaineer22 10y agoHow are the eBooks? Do you like them?
- coredog64 10y agoI am very happy with them. It wasn't full of fluff but was very targeted. I have the prior edition, so at some point I'll have to go back and buy the basic package again to upgrade.
- canada_dry 10y agoWhats especially great - and differs from most bloggers that are shamelessly shilling their wares - is that he provides a ton of excellent content on his blog. His book takes it to another level, but isn't necessary to get your feet wet.
- Houshalter 10y agoThere's an even cooler thing you can do with automatic grading. I saw this idea on another HN comment once. The computer can figure out the answers without programming them in. Or it can figure out mistakes in the real answer key. The idea is that answers are highly correlated. Better students are more likely to get all answers correct, worse students are more likely to make mistakes. So if you do something like PCA on all the students' answers, the first dimension will represent the quality of the student. And the weights will represent which answers are correct.
- eanzenberg 10y agoThat's pretty cool, like automated collaborative grading on a curve.
- toomuchtodo 10y agoMachine learning using human expert trainers ;) I wonder if Khan Academy has tried this yet.
- TD-Linux 10y agoClassic multiple choice grading machines will print out the number of incorrect answers on a final sheet passed through, next to each question (where the checkmark normally is). A lot simpler than PCA, but still pretty effective in finding mistakes, or gaps in course material.
- deleted 10y ago[deleted]
- tgb 10y agoInteresting, but how would PCA work with a discretely-valued, unordered, metric-less data like multiple choice answers? (Actual question, not snark, I only know the basics of PCA.)
- gbrown 10y agohttps://en.wikiversity.org/wiki/Dummy_variable_(statistics) https://en.wikiversity.org/wiki/Dummy_variable_(statistics)
- jrcii 10y agoI just need 20 years to modify this to grade my short and long answer tests and I'll be sitting pretty.
- teach 10y agoIf Gradescope[0] starts allowing public signups it might be sooner than you think.... [0] https://blogs.nvidia.com/blog/2016/09/02/gradescope-brings-ai-to-grading/ https://blogs.nvidia.com/blog/2016/09/02/gradescope-brings-a...
- honkhonkpants 10y agoSo back in the Bronze Age my teacher would collect all the scantron cards -- which by the way can already be automatically graded; that is the entire point of the scantron -- and put them on the overhead projector with the correct answers masked out. Overhead projector was more than bright enough to shine through the paper card. The teacher could easily grade the entire class in a minute or two, no cameras or computers needed.
- coredog64 10y agoI had a biology teacher who would put them into a plywood form and drive a nail through a giant stack of papers.
- honkhonkpants 10y agoI don't clearly understand how that is effective, but it sounds like fun, and a good way to impress kids.
- coredog64 10y agoShe would drive nails through the forms and then count where the marked answer matched the hole. I suspect she got her husband to help too. It was easy for the students to double check that their tests were marked correctly as well.
- sah2ed 10y agoI don't understand your story. How would the teacher use the projector to speed up scoring?
- milesokeefe 10y agoThe light would shine through each student's answer card and key, like when you press two sheets of sketch paper together. So any mismatches would be easy to see and mark as you scan down the card. It would only take a few seconds to score each card and there would be no cognitive load at all, as in you wouldn't have to evaluate any answers.
- swyphcosmo 10y agoDo you take off points if they don't use a #2 pencil?
- tropo 10y agoProcessing well-known forms (AP, PSAT, SAT, etc.) would be sweet. The one for AP is 4 pages in color, but one might have a greyscale printer or decide to print only one page of it.