I've used the KM3 numerous times, but would use it only with caveats for SSA. It's a norm-referenced standardized test, with age and grade norms, so it's subject to the same limitations as most other achievement tests with regard to grade equivalents (e.g., WJIV, WIAT-III, KTEA-3). IOW, typically, one should pay very little attention to grade equivalents. It does have a little more fine-grained item-level skills analysis, so it's probably slightly better for SSA/placement purposes than the other tests, but again, it's not intended to be a comprehensive measure of all skills expected at every grade level. It is a diagnostic measure in the sense that one should be able to identify gaps in critical math skills. That's not the same as being able to assure consumers that all grade-level skills have been mastered.
Most evaluators in schools should be familiar with the test.
