Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!husc6!cs.utexas.edu!pp!sundown!grudin
From: grudin@sundown.ACA.MCC.COM (Jonathan Grudin)
Newsgroups: comp.cog-eng
Subject: Re: consistency
Summary: Clarifying my position on consistency
Keywords: consistency, desktop metaphor, interfaces, computing environments
Message-ID: <83@sundown.ACA.MCC.COM>
Date: 10 Feb 89 06:54:49 GMT
References: <714@cogsci.ucsd.EDU> <1465@thumper.bellcore.com>
Organization: MCC, Austin, TX
Lines: 32

Ralph Hill and I don't differ fundamentally, but I don't think
it is worth trying to defend "consistency" to the degree he does --
it is not useful and can be misleading. When examined carefully, his
position reduces to "consistently do the best thing in every situation"
-- we can all agree on that but it isn't useful.

I attended a two-day workshop on User Interface Consistency at the CHI'88
conference. We spent several hours trying to define "consistency," then
gave up and moved on to a discussion of how to achieve this thing we could
not define. Why was it so hard? At least in part, it was because we wanted
consistency to be "good" and thus tried to contort the definition to
cover good designs and exclude bad ones, and that wasn't doable.

My paper does note the positive aspects of many forms of consistency,
especially for learning, although there are exceptions there too. But it
emphasizes the other side, which is that a consistent interface is often a
bad one. As I said in the summary, a leading cause of stubborn poor design
is consistency, consistency with the software architecture or some other factor..
And consistency is often absent in a good design: Consider an efficient
typewriter keyboard (QWERTY, Dvorak or whichever is your favorite). In what
sense is it "consistent" with anything other than itself?  Setting aside the
problem of learning a new keyboard, the most efficient keyboard may vary
depending on what language is being typed and depends crucially on aspects
of the hand and motor control. But saying the keyboard is "consistent with
the language" or "consistent with the hand" doesn't seem useful.

But if you are determined to defend "consistency," here is one possibility:
"Consistently maximize user efficiency and satisfaction." Because in order
to do that, you will have to focus your attention on the users' work, which is
where your attention is most usefully focused.

Jonathan