Assigns your chosen numerical value to the average measure of the non-extreme items, i.e., a criterion-referenced measure. UMEAN= and UIMEAN= are the same specification. The last UIMEAN= or   UPMEAN= values in the control file is actioned.

 

UIMEAN= and UPMEAN= are ignored when there are anchor values, IAFILE= or PAFILE=. Anchor values are treated according to UASCALE=

 

Table 20 gives the UMEAN= and USCALE= values for a conversion that gives the measures a range of 0-100.

 

Example 1: You want to recenter the item measures at 10 logits, and so add 10 logits to all reported measures, to avoid reporting negative measures for low achievers:

UIMEAN = 10

 

Example 2: You want to recenter and user-rescale the item measures, so that the range of observable measures goes from 0 to 100.

Look at Table 20.1. Beneath the Table are shown the requisite values, e.g.,

UMEAN = 48.3 ; this is the same as UIMEAN=48.3

USCALE = 9.7

 

For more examples, and how to compute this by hand, see User-friendly rescaling