This videotape demonstrates the Acronym help system,
an experimental help system for Unix
developed by Nathaniel Borenstein
as part of his dissertation research
at Carnegie Mellon University.
Although Acronym will run on standard video display
terminals, it was designed particularly
for hardware that includes a large screen
display and a mouse.
You are looking at a version of Acronym
on such a machine, a PERQ computer acting
as a terminal on a VAX Unix system.
The screen is divided into three major windows.
The top window is a help text window
in which texts are presented that explain Unix operating
system utilities.
The second window is a menu of further health topics.
The third window is the command window, a typescript window
in which the user types commands and views their output.
Here, with Acronym running on a smaller screen,
we will observe its behavior more closely.
When the user types the word help,
Acronym ask him for a keyword about which he desires help.
In this case, the keyword is mail.
And Acronym provides a list of mail related topics.
From this list, the user notices the mail command
and types the word mail, Acronym updates its display
accordingly.
Now, the user needs to type the name
of the recipient of the mail.
After typing the first letter, M,
he was uncertain of its spelling and so typed a question mark.
Acronym provided in its menu a list
of all valid local mail recipients that matched
what he had typed so far.
Menu selection is made with a mouse on hardware that
includes a mouse and with function keys when
no mouse is available.
The function keys serve another purpose as well.
Here at the bottom of the top and middle windows,
we see phrases like Select F11 to move forward,
using the function keys the user can scroll each of these
windows independently when their text cannot all be displayed
at once.
To envision Acronym in real use, imagine a novice user
seeking a list of his files.
He begins by typing, help, followed by the key word, list.
By scrolling through the menu that Acronym then provides,
he finds the LS command.
Now, that we have seen the basic mechanisms with which Acronym
is used, we can look briefly at the system as a whole.
None of the individual features of Acronym are new,
each has been implemented in some other help system
somewhere before but never apparently
have so many help mechanisms been integrated
to work from a common database with all
of the mechanisms available at any given moment.
This integration is Acronym's most important contribution .
Users need help in several different ways
at different times and there is no reason
to try to force them to make do with a single mechanism.
By making all of the mechanisms access a common database,
it becomes possible to give each mechanism a full component
of documentation information while minimizing the work
of the documentation writer.
Acronym, in its current implementation
runs on a VAX 11750 running Unix emacs.
Most of the code is written in mock Lisp, the emacs extension
language, although the computation intensive parts are
written in C and communicate with Emacs via the Carnegie
Mellon University Interprocess Communication facility.
Acronym's database is fleshed out
to include most of the Unix utilities
corresponding to section one of the Unix manual.
The Acronym database alone now occupies over half a megabyte
of disk storage.
Much of this space is taken by the help techs themselves,
but a large portion of it specifies
the syntax of Unix commands for purposes
of context dependent help and provides
lists of keywords for help requests,
thus simulating a thesaurus on keyword help requests.
The doctoral dissertation for which Acronym was developed
focused primarily not on the implementation of Acronym
but on the evaluation of alternative mechanisms
for online help.
Controlled experiments were conducted
in which Acronym was compared to several other help
systems for Unix including the standard help
system, a human tutor, and a simulated natural language help
system.
In these studies, Acronym fared better
than any other help condition except the human tutor.
Moreover, Acronym made up approximately 2/3
of the difference between the standard Unix help
system and the human tutor.
However, the experiments also indicated
that one of the best things Acronym has going for it,
is the quality of the help text's it uses.
A much simpler system that used the same text's Acronyms used
fared nearly as well as Acronym itself.