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Help desk => Questions and Answers => Topic started by: furonggao on April 19, 2019, 06:25:29 PM

Title: wle (or mle, eap) estimates using existing item parameters
Post by: furonggao on April 19, 2019, 06:25:29 PM
Hi,

Is there a way to let ConQuest estimates wle for cases with already (previously) estimated .prm files, without re-estimating the item parameters? If you have done so, would you mind sharing the commands you used to do this? thanks much!

Sincerely,
Furong Gao
Title: Re: wle (or mle, eap) estimates using existing item parameters
Post by: dan_c on April 22, 2019, 08:34:23 AM
by ".prn" files, do you mean exported item parameters, created using the "export" command?

https://conquestcommandref.netlify.com/commands.html#export (https://conquestcommandref.netlify.com/commands.html#export)

If so, yes, you can read in item parameters and use them as starting values or anchors using the "import" command. See:

https://conquestcommandref.netlify.com/commands.html#import (https://conquestcommandref.netlify.com/commands.html#import)

Remember that the item parameters exported are only those that are estimated. If you use the item constraint to identify your model, you're exported parameters will exclude the last item (which is the negative sum of the other items).

Another approach is to save the current state of conquest in a system file using the command "put". If you estimate a model, then write a system file, you can later read that system file back in and you won't need to re-estimate the model/calculate fit/gereate case estimates etc.

https://conquestcommandref.netlify.com/commands.html#put (https://conquestcommandref.netlify.com/commands.html#put)
https://conquestcommandref.netlify.com/commands.html#get (https://conquestcommandref.netlify.com/commands.html#get)

If you write a system file and also use R, you can read it into R using the conquestr library:

https://cran.r-project.org/package=conquestr (https://cran.r-project.org/package=conquestr)
Title: Re: wle (or mle, eap) estimates using existing item parameters
Post by: furonggao on April 24, 2019, 05:13:15 AM
Thank you so much, Dan! This is very helpful!!

Sincerely,
Furong Gao