Researchers in Artificial Intelligence have traditionally been
classified into two categories: the "neaties" and the "scruffies".
According to the scruffies, the neaties concentrate on building elegant
formal frameworks, whose properties are beautifully expressed by means
of definitions, lemmas, and theorems, but which are of little or no use
when tackling real-world problems. The scruffies are described (by the
neaties) as those researchers who build superficially impressive systems
that may perform extremely well on one particular case study, but whose
properties and underlying theories are hidden in their implementation,
if they exist at all. As a life-long, non-card-carrying scruffy, I was
naturally a bit suspicious when I first started collaborating with
Dieter Fensel, whose work bears all the formal hallmarks of a true
neaty. Even more alarming, his primary research goal was to provide
sound, formal foundations to the area of knowledge-based systems, a
traditional stronghold of the scruffies - one of whom had famously
declared it "an art", thus attempting to place it outside the range of
the neaties (and to a large extent succeeding in doing so).