"Desperate Dan" wrote in message
...

The only way to understand a site is to survey the site.

Sorry, but I don't really agree, or at least not completely. There's no
argument but that the gold standard is for a professional survey of each and
every site contributing data (to WOW in this particular instance). But
that's not practicable nor is it every likely to happen - although I
wouldn't exclude some more informed type of self-reporting/certification
than exists at present, maybe even encourage well-briefed amateurs in the
area to visit and comment.

However, that doesn't mean that all data from sites that haven't been
individually surveyed is equally bad and unreliable. Modern statistical
methods are quite powerful in monitoring the deviation of actuals from
gridded data calculated from the overall observational data set and should
quickly be able to prioritise site that offer consistently accurate data,
especially if the self-certification for exposure can be factored in too.
No-one is making the argument that this is ever going to be as good as data
from a well-exposed and professionally surveyed site, but I do strongly
suspect that this approach may well be more powerful than you might imagine.
Again I'd suggest looking at what CWOP does for the US.

JGD