

Hacking high school exams and foiling them with statistics - gridscomputing
http://hackaday.com/2013/06/05/hacking-high-school-exams-and-foiling-them-with-statistics/

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T-hawk
Blogspam, go here for the original.

[http://deedy.quora.com/Hacking-into-the-Indian-Education-
Sys...](http://deedy.quora.com/Hacking-into-the-Indian-Education-System)

That has all the real graphs. They make it really obvious that the test must
not be scored on a continuous spectrum, but is chunked into increments of more
than one point. But there are also some curious bimodal effects that could
indicate tampering at significant levels like 90%.

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refurb
Doesn't the pattern depend on the value of each question? For example, if you
have a score out of 100, but all questions are worth 4 marks, then you'd end
up with a series of grades that are multiples of 4 (assuming no part marks).

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VikingCoder
That alone can't explain how 94, 95, 96, 97, 98, 99, and 100 were all
achievable scores. Also each of the numbers from 0 to 32.

