5 points on an iq test is actually more than you might think.
That said, I have a child who tested 138 FSIQ on the WPPSI and six months later 146 on the SBV. Some kids test the same on both, some find one test suits them better than the other. It can also be the tester or just the day... In our case I put my DDs results down to:
1) she outright refused part of the WPPSI, this effected her score
2) the WPPSI was long and boring, i watched her tune out before she got to her level on multiple sub tests. Where as due to the routing questions the SBV was fast, snappy and engaging
3) the 2nd tester "got" my DD. the two testers themselves contributed to the long slow v. fast and engaging issues in point 2.
So yes retesting might drive the score up, but it might not. I think cricket's advice is excellent.
