Hello,
I'm new to ConQuest and trying to figure out how to run a Rasch Model analyses on a test with 33 dichotomously scored items. I followed the ConQuest tutorial on modelling a dichotomously scored multiple choice test with the Rasch Model but I get warnings and it seems to me that the analyses does not run properly.
And this leads to my first question. My Items already contain only two options (correct answer coded with 1 and incorrect answer coded with 0). Do I follow the right commands when following the ConQuest tutorial that provides a multiple choice test as example?
Second question - when running the analyses I get the following warning:
"Parameter (7) for item 7, is not identified. If anchors or initial values are used the referencing must reflect removal of this parameter." Item 7 is then excluded from the analyses. Unfortunately, I don't know what this warning means and what I can do to get Item 7 included.
Last but not least I looked at the provided itanal statement and it seems to me that something does absolutly not fit! E.g. with item 1 it says that 11 students responded with 0 and 88 responded with 1. But in fact, 99 students responded this item correctly which is coded with 1 for all students (the coresponding collum in the data file does only contain 1, no 0!) What has happend here? Is it possible that ConQuest mixed up the collums? And can I trust the provided parameter estimates and the map of item difficulty parameters if the count of students who responded to the items does not fit?
Thank you for help!
Kind regards, Johanna