Frequently Asked Question:

How much overlap is there between the Preschool Language Scale—Fourth Edition and the Bayley–III Language Scale?

Answer:

There are only 44 items in the Bayley–III Language Scale that originated from the PLS-4. A validity study between the PLS–4 and the Bayley–III indicate no practice effects between the two tests, so administration of one test does not affect performance on the other test.