Author Topic: Disordered initial values after deleting items in a previous step  (Read 616 times)

georgeha

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I'm examining a within-item multidimensional model, so I am exporting the item parameter file to specify these as initial values in the next step.  I am excluding the 2nd item, however, because it is not part of the model I am investigating (but I wish to retain the item numbering I have).  If I exclude this item, using "DELETE!items(2)" does the second step read a disordered set of initial parameters (offset due to the deleted item)? The error, "If anchors or initial values are used the referencing must reflect removal of this parameter" to me suggests the ordering gets messed up. 

If the initial values are indeed disordered, what is the easiest way to ensure the ordering is correct?

Eveline Gebhardt

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Re: Disordered initial values after deleting items in a previous step
« Reply #1 on: January 07, 2014, 03:03:03 AM »
Good question. I have done this many times, but can never remember what actually happens. Easiest way to find out is to do a run with only one iteration, set the standard error to quick and fit to no in the estimate command. Instead of using initial vales, you could anchor the deltas, so you can carefully check in the show file if any of your deltas or step parameters have been shifted due to the deletion and if the item numbers skip number 2.

Eveline


georgeha

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Re: Disordered initial values after deleting items in a previous step
« Reply #2 on: January 08, 2014, 12:54:23 AM »
Good suggestion. After running a second step with the first step's anchored parameters, I see the sequence is correct (the difficulty estimates match the original item numbers). So, the Delete!Item(n) does not appear to be messing up the sequence.  This is good.

Eveline Gebhardt

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Re: Disordered initial values after deleting items in a previous step
« Reply #3 on: February 11, 2014, 09:47:47 PM »
Excellent.