It tests knowledge of letters and letter sounds, basically. It's a reading readiness test. A 169 is well above the fall benchmark, but I would guess it is an average score in Fairfax County. My now 3rd grade DS, who has always been an average reader, had a similar score (can't remember exactly). My 1st grader, who is a strong reader, scored higher.

5yo DS scored 169 on this test but he cannot yet read. He does know some sight words. K teacher implied that he scored high but we don't have any percentiles.