Anchor (fixed) values for the persons are specified by PAFILE= and for the items by IAFILE=. All the anchor values can be increased or decreased by the same amount using UAMOVE=. The value is applied before any rescaling with UASCALE= or USCALE=. UIMEAN= and UPMEAN= are ignored.

 

Reported values = USCALE= * (UAMOVE= + anchor value)/UASCALE=

 

Example 1:  All anchor values are to be increased by 1.5 units for this analysis:

IAFILE = *

12 2.5      ; the anchor value for item 12 is 2.5 units

*

UAMOVE = 1.5 ; the amount by which to increase the anchor values

Item 12 will be reported in Table 14 with an anchor value "A" of 2.5 + 1.5 = 4.0 logits.

 

Example 2: Anchor values in logits centered on 0. Report values to be user-scaled 100 units per logit, centered on 500.

UASCALE=1

USCALE=100

UAMOVE = 500/100 = 5

IAFILE=*

1 0.5   ; 0.5 logits

*

Reported value = 100 * (5 + 0.5) = 500 user-units