How to make the application intelligent to grade answers?

I am adding a feature to an application in which the students answer questions that are more descriptive in nature. I am curious to know if there's a way to make the system "smart" enough to grade these answers. Ofcourse, I can run the answers through a set of keywords to ensure that the student has atleast included the keywords in the answers, but obviously this is not smart enough.

I know there's no fool proof way of grad开发者_StackOverflow社区ing descriptive answers, but was wondering if there's any technologies out there that I can look into.

You could use mechanical turk which is an API for humans. Which is probably as far as you can get with AI'ing your system. Understanding and grading actual text is one of the last remaining problems where humans are way better than computers (i.e. computers suck)

One notable exception is Watson which is actually really good at Jeopardy, but it runs on a huge computing cluster and includes some serious optimizations and smarts. That's nothing you just turn on. Sorry...

The answer is not so simple. There are "automated grading systems" out there, used, I believe, for example, to grade GRE exams. For example, see this paper and this by ETS.