Discrimination parameter

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kerensm
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Joined: Fri May 20, 2022 6:34 am

Discrimination parameter

Post 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
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seol
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Re: Discrimination parameter

Post by seol »

Hi kerensm

you can check it by using Distractor analysis within snowIRT module.

Seol
kerensm
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Joined: Fri May 20, 2022 6:34 am

Re: Discrimination parameter

Post by kerensm »

Would you please explain how to do this and what result displays the parameter?
kerensm
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Joined: Fri May 20, 2022 6:34 am

Re: Discrimination parameter

Post by kerensm »

I did it. But I do not understand what parameter displays it. The infit for example parameter shows the difficulty.
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seol
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Re: Discrimination parameter

Post by seol »

You will find it by using example .omv file in the Data Library.
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kerensm
Posts: 5
Joined: Fri May 20, 2022 6:34 am

Re: Discrimination parameter

Post by kerensm »

Thank you!
what does this error message mean: "data must be data frame or matrix"?
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seol
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Re: Discrimination parameter

Post by seol »

Would you send me .omv file that produced error at snow@cau.ac.kr?
kerensm
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Re: Discrimination parameter

Post by kerensm »

I appreciate your help. Thank you very much.

I'll send the file soon.
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