As a Vocational Evaluator, I'm tasked with producing grade-levels, based on another clinician's work. He used the Woodcock-Johnson to produce standard scores, but he didn't include grade-levels. I solve this problem by using the Wide-Range Achievement Test IV tables to convert SS to raw scores, which I then plug into the corresponding WRAT age-based grade-level tables, to get GL. What can I call this process. I don't like extrapolation, interpolation or estimation. What else is there?