And, BTW, it is possible to derive predicted achievement from the SB to the WJ, if you want to know if the achievement scores are comparable to the cognitive. A few points difference is generally not a big deal.
Just to clarify... a derived WJ score is used to check for relative consistency between the SB IQ score and an actual WJ achievement score... in other words, the derived score is not an actual WJ achievement score... calculating a derived WJ score does not eradicate the need for WJ achievement testing?