Page 1 of 1
Discrimination parameter
Posted: Fri May 20, 2022 6:44 am
by kerensm
Hi
In the polytomous model (IRT), I need some guidance on finding the discrimination parameter (slope (a))- which indicates how well items discriminate between different levels of the underlying trait.
I developed a scale and would like to test it.
Thank you very much
Keren
Re: Discrimination parameter
Posted: Fri May 20, 2022 11:42 pm
by seol
Hi kerensm
you can check it by using Distractor analysis within snowIRT module.
Seol
Re: Discrimination parameter
Posted: Sat May 21, 2022 6:03 am
by kerensm
Would you please explain how to do this and what result displays the parameter?
Re: Discrimination parameter
Posted: Sat May 21, 2022 6:15 am
by kerensm
I did it. But I do not understand what parameter displays it. The infit for example parameter shows the difficulty.
Re: Discrimination parameter
Posted: Sat May 21, 2022 8:51 am
by seol
You will find it by using example .omv file in the Data Library.
Re: Discrimination parameter
Posted: Sat May 21, 2022 2:31 pm
by kerensm
Thank you!
what does this error message mean: "data must be data frame or matrix"?
Re: Discrimination parameter
Posted: Sat May 21, 2022 11:11 pm
by seol
Would you send me .omv file that produced error at
snow@cau.ac.kr?
Re: Discrimination parameter
Posted: Sun May 22, 2022 6:00 am
by kerensm
I appreciate your help. Thank you very much.
I'll send the file soon.