Path: utzoo!utgpu!water!watmath!watcgl!drforsey
From: drforsey@watcgl.waterloo.edu (Dave Forsey)
Newsgroups: comp.cog-eng
Subject: Re: Using kinesthetic memory for human interfaces
Message-ID: <4988@watcgl.waterloo.edu>
Date: 24 Jun 88 20:04:20 GMT
References: <3535@pdn.uucp> 
Reply-To: drforsey@watcgl.waterloo.edu (Dave Forsey)
Organization: U. of Waterloo, Ontario
Lines: 67

In article  eric@snark.UUCP (Eric S. Raymond) writes:
>In article <3535@pdn.uucp>, colin@pdn.UUCP (Colin Kendall) writes:
>>The experience has deepened my respect for muscular memory,
>>Studies have shown that
>>after a little practice, users of these menus no longer need to
>>look at the screen while making menu selections, even complicated
>>cascades of selections!) 
>
>This suggests a more general question. What can we do (besides pie menus, which
>I agree are neat) to maximize the extent to which the user's model of routine
>operations is embedded in kinesthetic memory (NLP, anyone ;-)?).
>

We've been using some sort of radial selection menus since '84, and my
personal experience indicates that even 4 or 5 ( 7 +- 2? ) levels of
hierarchy is still quite managable without much cognitive burden.
I don't know if this (subjective) feature would offset the limits that
pie menus have (i.e. it is hard to put 15 items around in a circle
and have people select easily). They seem (to me) to be an order of
magnitude easier to use than these menus in which you slide the cursor
off the item to one side to pop-up the next level of the hierarchy.

A significant speed-up occurs after using a set of menus for a period
of time.  Careful arrangement of the menu items can aid in this.
(as Callahan, Hopkins, Weiser and Shniederman (CHI '88), have noted).

I'm not sure that the raw speed increase is as important as the ease in
which they can be used. I hardly even look at the items on the menu anymore,
just the overal appearance (which differ in size according to the number
of items and the length of the words contained therein) seems to be
enough to guide my choices.  

I've had no experience with the Callahan et al style, but in our version
the sub-menu pops up when the cursor enters any part of the pie sector 
(no additional button action is required).
As an aside with regards to the automatic cursor motion question,
when the sub-menu pops up the cursor moves to accommodate the new menu
position, but since i'm operating mainly through a gesture this does
not seem to bother me. (How one might quantify this effect and test it
is not clear).

I tend to think of radial selection menus as gesture recognition
with visual feedback.  Many will remember the character recognizers that
researchers were trying a couple years back. Buxton out of the University
of Toronto had a pilot system in which the menu selections were made by
the system recognizing gestures made by the user on the screen.
Hierarchical radial selection menus have the potential to provide a
very similar function since equivalent "gestures" will take you to the
same menu item.

This ability will of course vary with the target size etc,
and some gestures will be easier to do than others (noted again by
Callahan et al.) and all these extra variables will mean that the efficacy of
the pie menus will be highly dependent on the skill of the interface
designer (this is not news).

Terry Higgins, formerly of this lab, demonstrated a paint system with
radial selection menus (that also featured mouse-ahead and couple of other
interesting ideas) at SIGGRAPH '87 last year. This year i'll probably
have a couple systems at the iris users forum that use a type of pie
menu. Not as nice as Terry's, but functional for the purposes of the
programs.

Dave Forsey
Computer Graphics Laboratory
University of Waterloo
Waterloo Ont. CANADA