Roy Williams wrote:
> Most interesting to astronomers, I think, is documentation of what
> a parameter actually means, and we have that right from the start
> with the Description tag. While some technical people are most
> interested in an Xschema description, I think this is of less
> interest to astronomers, and would in reality be a big roadblock to
> entry.
I think we're in the classic computer science vs. astronomy argument that has dogged the VO throughout it's entire life. Most of the people who are going to have to sit down and implement the creation (and parsing of) VOEvent messages aren't computer scientists or "real" programmers (defined by for the sake of argument as someone who, when they've written a recursive routine actually knows they've done it).
For the most part they're astronomers who will view the messages as text, plain ASCII text. If 1 in 10 end users actually use an XML parser to rip a VOEvent message apart I'll be really surprised. Even those astronomers who will use an XML parser to create or parse the message will, again for the most part, not be comfortable with schema. I'd lay money on the fact that the only astronomers to verify the messages against the schema will be those whose parsers do it for them behind their back and don't tell them. Having to create entirely new schema every time you want to add the equivalent of a <Param> to a message would be seen a serious stumbling block. In reality what would happen is that people would start making tags up without creating the schema to go with them and you'd end up in a situation far, far, far, worse than having <Param> tags with UCDs attached to them. Although admittedly we're in the situation even right now where I'm to "make up" a UCD-like entity to tag my <Param> with, at least that's better than making up an entire element like <tau_max>, the consequences of which I hate to think about. Don't fool yourselves, it'd happen. At least at the moment you can verify the message against the schema, I doubt you'd be able to do that a couple of years down the line if we went down the alternative route. Need I mention FITS headers? Let alone the ESO "extensions" to FITS headers?
Al. Received on 2006-08-08Z11:27:01