Well, if you’re content to just go with what the parents tell you, then that’s up to you. It certainly would be quicker and I’m sure you have very thorough questions.
Parents are not always the best judges, however, when it comes to their children’s behaviour - they’re used to their kid always being that way, it’s ‘just Johnny,’ and they’re hardly objective. Plus, children often behave very differently away from their parents; a lot of the problems people with Asperger’s have come up in situations like school, interacting with their peers, rather than situations where they have a trusted adult to hand.
My daughter’s mostly fine when she’s with me and my friends, because I guide her in ways that it took me a long time to even notice I was doing and my friends are all easygoing with her.
ISTM that you’d be missing out on a hell of a lot of information by not making at least a few observations of the kids in situations where their parents aren’t present - and on more than one day, because everyone has good and bad days.
Didn’t say that I just go with what the parents tell me. Observations of the child are crucial as well, and contemporaneous teacher reports are also important. And, as I’ve said before, having multiple observations over time will help improve the confidence you have in the diagnosis. It may also help to resolve the problem of diagnosing a problem that falls just the other side of the pathological/non-pathological divide.
That doesn’t mean that the observations take six years or that a cross-sectional evaluation is worthless.
You’re talking about justifying or explaining a cause of the behavior, rather than reporting on the actual manifestation of the behavior itself.
This is true of ADHD, oppositional defiant disorder, anxiety problems, mood problems and many other conditions. Of course different contexts will affect the display of behavior differently.
Improvement over time, if delayed and impaired, is still typical of children with PDD. Markedly variable demonstration of behavioral skills over a short period of time is not. Knowing that would of course be useful from a diagnostic standpoint, but it’s suggestive of something other than Asperger’s Disorder.