plots=IIC in proc IRT

[lboyd]

I am running:

ods graphics on;
proc irt data=ff1 RESFUNC=graded plots=iic;
   var fv_preptime    fv_fresh    fv_prepknow    fv_filling    fv_restarauntserv    fv_sugar    fv_dontlook    fv_costtoomuch;     
run;
ods graphics off;

on data that has 5 categories (ie. never, rarely, neutral, often, and always).  I am trying to get IIC plots, not ICC plots, but I keep getting an error:

NOTE: The IRT procedure is experimental in this release of the SAS system.
103  proc irt data=ff1 RESFUNC=graded plots=iic;
                                            ---
                                            1
WARNING 1-322: Assuming the symbol ICC was misspelled as iic.

I have run it other ways including plots=all, plots=(scree(unpack) iic) and I just can't seem to get the IIC plots.

Any suggestions?

Thanks!

[Rick_SAS]

Try it on a simple example. Perhaps there is something degenerate about your data:

data IrtUni;
   input item1-item8 @@;
   datalines;
1 0 0 0 1 1 2 1 1 1 1 1 1 3 3 3 0 1 0 0 1 1 1 1 1 0 0 1 0 1 2 3 0 0 0
0 0 1 1 1 1 0 0 1 0 1 3 3 0 0 0 0 0 1 1 3 0 0 1 0 0 1 2 2 0 1 0 0 1 1
3 3 0 1 0 0 1 2 2 1 
; 

proc irt data=IrtUni plots=ICC;
   var item1-item8;
run;

[lboyd]

Hi Rick,

Thank you for your response!  I just ran what you posted and changed plots=IIC and I still got this error:

237  proc irt data=IrtUni plots=IIC;
                                ---
                                1
WARNING 1-322: Assuming the symbol ICC was misspelled as IIC.

Any other thoughts as to why it doesn't like IIC?

My data is 5 categories (strongly agree=1, agree=2, neutral=3, disagree=4, and stronlgy disagree=5).

Thank you!

[Rick_SAS]

The IIC plot was introduced in SAS/STAT 13.2.  (13.2 = SAS 9.4m2) I conjecture that you are running 13.1 and so that plot is not available.  You can check your SAS version by using

%put SYSVLONG = &SYSVLONG;

[lboyd]

I have SYSVLONG = 9.04.01M1P120413

[Rick_SAS]

Right, and the M1 means you are running SAS 9.4m1 = SAS/STAT 13.1.  There have been three releases of SAS since then (13.2, 14.1, and 14.2).