Path: utzoo!utgpu!water!watmath!clyde!att-cb!att-ih!pacbell!ames!ucsd!sdcsvax!ucsdhub!hp-sdd!hplabs!hpcea!hpfcdc!hpfclp!diamant
From: diamant@hpfclp.HP.COM (John Diamant)
Newsgroups: comp.windows.misc
Subject: Re: Re: A/UX window systems, Mac tool...( Hum Interface) (calibration)
Message-ID: <10700002@hpfclp.HP.COM>
Date: 1 Apr 88 23:32:20 GMT
References: <6895@drutx.ATT.COM>
Organization: HP SDE, Fort Collins, CO
Lines: 32

> It is impossible to define modedness well enough to allow experimental
> comparisons of moded and non-moded systems.  The sentence is cute, but
> untestable ... one of Xerox's design tenets was "Evaluate alternatives"
> and a better tenet.  Now when someone implements a truly modeless
> complex application, then we'll be able to make sensible comments
> by EVALUATING the true effects of increasing modedness on human performance
> when interacting with computers.
> --
> Gilbert Cockton, Scottish HCI Centre, Heriot-Watt University, Chambers St.,

Not true.  Emacs is a good example of a modeless editor (in contrast to
vi).  Now, I know you are immediately going to object (if you are familiar
with emacs) that the language major modes and minor modes (like auto-fill)
are really modes.  Well, that's true, except that emacs is a very usable
editor without any of these.  You can consider the editor to be a Lisp
editor, a Text editor and a C editor all in one, rather than a moded
language-sensitive editor, and have a completely consistent view.  You
need never notice the modes if you use it on the same "language" (including
text here as a language) in all cases.

It's command model is based on the principle that all keys mean the same
thing regardless of whether you are inserting text or not.  Again, you
may object that multi-keystroke sequences are modal, but they needn't
be viewed that way.  Unlike insert mode in vi, the "modes" of multi-keystroke
sequences are only active for a single keystroke, and so never need to
be internalized as a mode by the user.


John Diamant
SDE				UUCP:  {hplabs,hpfcla}!hpfclp!diamant
Hewlett-Packard Co.		ARPA Internet: diamant%hpfclp@hplabs.HP.COM
Fort Collins, CO