Hamilton.es@PARC-MAXC@sri-unix (08/06/82)
Folks seem to be talking about menus in what is still basically a single-window, TTY style of interaction. I don't doubt that they usually lose in such an environment. But having worked for several years in the Mesa environment, where many tools let the user use any combination of typein and pop-up "hint" menus, I can say that mouse plus pop-up menu always wins if the typein is more than two or three characters -- and I'm a good typist. (Assuming the menu pops up instantly; sometimes it can take several seconds to paint, due to swapping.) The menu item can typically be called up and invoked in less than one second, with a single click-sweep-release of the mouse. I believe similar figures would apply to Interlisp-D and Smalltalk. --Bruce
Black@YALE@sri-unix (08/11/82)
From: John Black <Black at YALE>
People have been talking as if menus were necessarily good things,
except that they might sometimes slow down expert users. I submitt that
menus can also lead to worse performance than merely allowing users to
generate commands. This relates to an issue in cognitive psychology called
recognition failure of recallable words. Menu systems rely heavily on
recognition memory: i.e., you have to look at the list of commands on a
menu and recognize the appropriate one. Without a menu, on the other hand,
the user has to recall the appropriate command.
Well, for a while psychologists thought that recognition was always
better than recall (i.e., that menu systems were better), but then cases
were found where people could recall something learned earlier while failing
to recognize it. This somewhat paradoxical behavior occurs when the context
in which a person is trying to recognize something emphasizes a different
perspective than that in which the material was learned. Let me give an
example using a fictional text editor. Suppose this editor uses the
standard sort of terminology -- namely, insert, delete, replace, etc. Now,
if a user wanted to add a letter on the end of a word (e.g., make the word
plural), then he or she would probably have little trouble recalling "insert"
as the correct command. However, suppose the user was confronted with the
following menu:
insert
delete
replace
append
preface
Now the user might well fail to recognize the correct command -- probably
even erroneously choosing "append." But surprise, append and preface refer
to adding lines to the end and beginning of a file. The problem here is that
the presence of append and preface on this menu emphasize the meaning of insert
as putting something in the middle rather than as adding anything. Thus unless
one is very careful it is easy to design menus that users will find confusing
in this way -- particularly, novice users that the menus are supposed to be so
helpful for. This example is simple, but the potential confusions are not
always so easy to see.
-------