# educational measurement

1. ### Item Response theory In variance

Hi, I am working on Educational assessment item calibration task. I am new to IRT and I have read 100s of papers still could not wrap around my head with invariance property of IRT and item calibration. My question is suppose I have response data of 20,000 students on 10 items, now I want to...
2. ### comparing two independent binomial data sets, unequal size, Welchs t-test?

I would like to compare the pass rates of two different classes (say English 111 and English 113). The data is binomial (0= fail, 1=pass). The sets are unequal size. I think its safe to assume independent population means and unknown SD. I am inclined to use Welch's t - test. But I am not sure...
3. ### significant change in binomial data?

I want to determine how much of a change in pass rates do I need to observe for it to be statistically significant. For example: pretend there are 2,000 people who took English101 in the last 4 years, and 1500 of them passed the class. 1500/2000 = 0.75 pass rate. I want to set a goal of...
4. ### How to determine the number of items needed to design a reliable test

An educational assessment form equivalence problem. I produce a large (infinite?) pool of items similar in quality. I administer a test that uses items from the pool. For each testee, items are drawn at random from the pool. The testees respond to x number of items. If I need a reliability...
5. ### Where to send an education methods piece

I'm writing a piece that introduces a new correlation like measure between time periods. I would like to get this one published somewhere. The problem... My mentors are qualitative people. Generally the work I read is qualitative (my field is very qual) and so my exposure to journals with...