Hi,
I am pretty new to Stata and IRT. Using IRT 2PL model, I tried to estimate item difficulty and item discrimination parameters. There are 17 items (binary: 1-yes, 0-no) and the sample size is only 31.. I admit the sample size is too small, but anyway I analyzed it and most of item discrimination parameters were negative values. Can anyone explain the negative discrimination? Does it simply mean that I cannot trust the results from a small sample size or that item coding is wrong, etc? Plus, how can I check df for each item?
Thank you in advance!
Related Posts with IRT 2PL parameters
Re-arrange variablesDear all, I have 30 variables in different columns. Now I want Stata to generate one new variable w…
IV regression with multiple interactionsHello, I hope you could help me with this. I need to estimate three separate equations with -ivreg2…
Marginal Effects on ivprobitI'm running an ivprobit model, and I'm trying to get marginal effects out of the second stage coeffi…
Combining two variablesHello, i'm just working on a do-file and I'm struggeling to combine to variables. The first variable…
Calculating BMI when ht and wt have been recorded with different unitsHello, I am trying to create a new variable for BMI and I have a dataset with continuous variable "…
Subscribe to:
Post Comments (Atom)
0 Response to IRT 2PL parameters
Post a Comment