Re: [SIGCIS-Members] Virtuality versus transprency -- trying to locate a quote about the difference

I heard it from Mike Williams, when he had his professor of computer science hat on! Here's how he said it:

If it is there, but you can't see it, it is transparent. If it isn't there, but you see it, it is virtual. If it is there, and you see it, it is real.

For the purposes of symmetry, what if something is not there and you can't see it?

If it isn't there and you can't see it, you're ok. David