Person anchoring can also facilitate test form equating.
The persons common to two test forms can be anchored at the values for one form. Then the measures constructed from the second form will be equated to the scale of the first form. Blanks of non-numeric values indicate no anchor value. The third person in the test is to be anchored at 1.5 logits, and the eighth at -2.7. Jo 111110011101 etc.