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I didn't really follow the math here but is a simpler solution just to give different questions different points? 1. What is ...? (Worth 1 point) 2. What is ..
by jon6 14y ago
I didn't really follow the math here but is a simpler solution just to give different questions different points?
1. What is ...? (Worth 1 point)
2. What is ...? (Worth 2 points)
It looks like IRT is for somehow determining the difficulty of a test given the answers of students.
- Semaphor 14y agoYeah, the article seems to start at a weird point. An algorithm to find out how many points a given question is worth might be better than having the teacher just decide what is worth how much. Or it might be worth. But what kind of stupid school system would grade math per question instead of per difficulty?
- achompas 14y agoI'd agree, if finding such an algorithm was easy! :)
- achompas 14y agoThe beauty of item response theory is that you can infer both the test's parameters and the student's abilities. You can use EM or Gibbs sampling to estimate those parameters simultaneously, so there's no need to limit yourself to test difficulty or student ability. In your described scenario, who decides each question's difficulty? Are we sure the teacher or test author understand the true difficulty of their questions? This kind of grading scheme is marginally better than some super-naive approach, as we can't be sure the professor fully understands each question's difficulty.