[Rasch] Removal of Participants
rmt at rasch.org
Thu Jan 12 14:33:46 EST 2012
Thank you for question, J.
The general rule is: "When in doubt, analyze the data both ways. Then base
your decisions on the analysis that makes the most sense."
See, for instance, http://www.rasch.org/rmt/rmt234g.htm
At 1/11/2012, you wrote:
>I have a large sample size of n=3798 persons to Rasch analyze a survey
>instrument of 14 items (with 4-point ordinal response options.). Using
>Winsteps, I noticed that the person measures ranged from -12.16 to 7.16
>logits. I noticed further that around 500 persons with logits/measures
>of greater than 7.0 have outfit and infit mean squares of zero..Many
>persons (around 800) have outfit and infit mean squares outside the 0.5
>to1.5 range. Is it a good practice to remove or exclude the persons from
>the analysis those with zero outfit and infit mean squares?
>Your inputs are highly appreciated.
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