From: bcoleman@hayes.com (Bill Coleman)
Newsgroups: comp.sys.mac.advocacy
Subject: Re: When is a CLI faster than a GUI?
Date: 6 Oct 92 15:21:39 EDT
Organization: Hayes Microcomputer Products, Norcross, GA

In article <1992Oct3.205125.14328@news.th-darmstadt.de>, wallmann@backus.pu.informatik.th-darmstadt.de (Natuerlich!) writes:
> In article <6114.2acc7f7e@hayes.com> bcoleman@hayes.com (Bill Coleman) writes:
> 
>>But the experienced graphic user interface user has the same advantage.
>>He can anticipate results, plan ahead, and keep an accurate model of
>>the human-machine system in his head.
> I'd just argue that with the mouse, you can't pipeline commands to begin
> with, 

You can. I do it all the time.

> that the machine response time is larger than with a CLI and that
> time expended on physical motion is quite large.

Let's hold the "machine response time" question for a moment.

The physical motion required to manipulate the mouse is quite small. Indeed,
once you add up all the keystroke distances, the mouse motion competes quite
well.

But this is silly, no one has ever gotten a workout from using a computer,
the physical motion required is minimal in either case, keyboard or mouse.
The time required for such a minimal amount of motion also must be minimal.

Getting back to "machine response time." Why is it necessarily larger for a
graphic interface than a CLI? Part of it could be that the graphic interface
does more. For example, when you drag an icon to another disk window, it
not only copies the file, but it displays the icon in the new place in the
window, and updates ancilliary information (such as the disk space used). To
acheive the same results in a CLI would require several commands. 

But I don't believe the machine response time is significantly different
in either case, given similar tasks. 

>>(The user interface designer in me asks the question -- why the heck do you
>>have to press "esc"? Why not just match the command as you type, and erase
>>your match if the user types more -- I implemented an interface like this
>>for file name matching in Smartcom III and Smartcom Exec)
> The Symbolics does this too. I don't know whether it's the response time
> or what, but I always hated it.

Well, it is certainly better than pressing 'esc'. If you knew you had enough
to match by the time you remembered and pressed esc, then you wouldn't need
to have the matching, you might as well just type the whole thing to start
with.

The first system I'd ever seen with this sort of command completion was
the system console of a CDC Cyber NOS system. Typing "CHE" would result
in "CHECKPOINT SYSTEM" being spelled out. At the time, it was cool.

>>Command completion doesn't seem to be very useful. The only thing I can
>>see is that is saves a few characters of typing. You still have to remember
>>the right command in the first place. It would make long command names
>>more palatable, however.
> BTW if you just remember the first letter[s] you can press [ctrl]-[d]
> in csh and it gives you the list of possible matches.

Again, the benefit is extremely limited.

-- 
Bill Coleman, AA4LR                ! CIS: 76067,2327    AppleLink: D1958
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Disclaimer: "My employer doesn't pay me to have opinions."
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Newsgroups: comp.sys.mac.advocacy