About Pearson Assessment age format
Pearson Assessments (publisher of the Wechsler scales, KTEA-3, BASC-3, CELF, and many other standardised tests) requires chronological age to be entered in Years–Months–Days format using the calendar borrowing method. Incorrect age entry directly affects derived scores and norm comparisons.
Calendar Borrowing Method (how Pearson calculates age)
1
Start with: (testing date) − (date of birth)
2
If day of testing < day of birth: borrow 1 month from the month column; add the number of days in the preceding month to the day column
3
If month of testing < month of birth (after borrowing): borrow 1 year; add 12 to the month column
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This produces a result identical to what Pearson Q-global computes — no rounding to nearest month.