Lots of good comments above. I'll just add:

1.Clarifying: the WISC-V can be taken once every two years.
2.Rapport is very important.
3.Any competent psychologist can obtain a good set of scores. It's the interpretation and recommendations that depend on an expert clinician.
4.You and your child both need to feel comfortable with the evaluator; you need to be able to trust the outcomes.

...pronounced like the long vowel and first letter of the alphabet...