Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!munnari.oz.au!uniwa!DIALix!dent
From: dent@DIALix.oz.au (Andrew Dent)
Newsgroups: comp.human-factors
Subject: Re: Individual Differences
Message-ID: <1063@DIALix.oz.au>
Date: 24 Jun 91 10:55:25 GMT
References: <80905@eerie.acsu.Buffalo.EDU>
Organization: DIALix Services, Perth Western Australia
Lines: 29

In <80905@eerie.acsu.Buffalo.EDU> palan-t@acsu.buffalo.edu (thiagarajan palanivel) writes:

>My own work is focussed on whether there exist any pairings between users' 
>cognitive profiles (the combimation of cognitive processing abilities and 
>capacities of a user) and the INTERACTION STYLE/PRINCIPLE of an interface (e.g. Command Language based, or Direct Manipulation based), that optimize performanceat the "operating system level" (domain-inspecific tasks like manipulating and 
>managing files, and navigating through file hierarchies). For example, can one 
>predict that a user with high verbal and reasoning skills but relatively low 
>spatial skills, will perform (the same task) better on a Command Language based interface, than on a Direct Manipulation based interface. From a different pointof view, can one say for example, that verbal ability is the single best 
>predictor of performance on a command language interface ?
Speaking in a non-scientific way, I have a concern that your definitions of
style/principle will not test the true power of direct manipulation as used
by "power users". Most Mac applications I've used have a wealth of command-key
combinations and shift-click/option-click/command-click etc. mouse actions.

The skills or type of cognitive profile which makes a user extremely 
productive on a CLI is (IMHO) directly applicable to the use of these "power-
user" facilities. These facilities often lack visual feedback that you are
in a "mini-mode" (unlike selection of graphics tools from a palette, or click
and drag to get some rubberbanded outline).

Without testing this kind of environment you run the risk of comparing the
"athletes" of the CLI against the "joggers" of Direct Manipulation.

public comment invited...

Andy Dent                     A.D. Software phone 09 249 2719
Mac & VAX programmer          94 Bermuda Dve, Ballajura
dent@DIALix.oz                Western Australia  6066     
dent@DIALix.oz.au (international)