The author’s own lack of knowledge is striking, as the “limit” for where he puts his level 5 is highly fluxuating.

Consider “Databases”. Where does knowledge about database partitioning fall in? Object Oriented databases vs Relational Databases?

Or “Scripting”. “Has written and published reusable code”… !?

And since when was knowledge of Prolog indicative of anything other than being around for waaay too long?

I see where he’s coming from however. But this matrix is hardly based on anything other than the author’s reflection of himself.

If you are interested in the subject matter, I would highly recommend swinging by http://www.construx.com/Page.aspx?hid=948 (you will need to register, but it’s worth it) and have a look at the wealth of information found here.