What *scale* are we using here...?

I volunteered to help with a local hedge survey. To be honest, I'm not entirely sure what a hedge survey is, and the info supplied did not greatly enlighten me - but I thought it sounded interesting and assumed someone would tell me more before I got too involved.

Now I have an invite to a 'training day' with a form to fill in that asks (in Avenir 35 light, an unusual choice of font, though undeniably cheery):
"I would say that my skills/experience/knowledge of landscape archaeology is: poor / fair / good / high / expert

I would say that my skills/experience/knowledge of plant species identification is: poor / fair / good / high / expert "

I have no idea how to answer these questions. I'm tempted to say 'poor' for both, on the grounds that then I'm not raising expectations and presumably they are assuming a level of basic interest from the fact that I've volunteered at all?   But then my plant species identification is better than my landscape archaeology, so maybe that should be fair. Except I'm not sure how fair, good, and high are different, they sound like Tolkienien elf-descriptions. But presumably they are on a sliding scale of some sort.  If you were high, would you graduate to 'expert' if you wrote a book? 

It also asks about 'relevant qualifications' which I always feel is a 'how long is a piece of string' question in a very Dirk Gently, fundamental-interconnectedness-of-all-things manner.