Reprinted from CHI ‘98 Conference Summary, pp. 18-19. © 1998 ACM.
Copying by permission of the Association for Computing Machinery.
This paper was the introduction to the live demonstration of Lisa.
Apple’s Lisa, introduced in January 1983, was the bridge between the
first commercial graphical desktop system, the Xerox Star (April 1982), and
the Apple Macintosh (January 1984), which popularized it. Although visually
similar to current graphical user interfaces, its user model differs
substantially. The live demonstration presents a broad view of the Lisa user
interface and relates it to other systems. This extended abstract focuses on
elements of Lisa’s document-centric user model and context management
that made it easier to learn and use than today's systems.
Lisa development started in 1979. Intended for general office use, it was
to be easy to learn, forgiving of errors, allow for interruptions, robust in
the event of failure and, most of all, be fun to use. The user interface
design evolved through several iterations  and was influenced during
development by ideas introduced by the Xerox Smalltalk  and Star 
systems. The Lisa adapted these ideas to a stand-alone personal computer with a
smaller screen and an open software environment, and added several new elements
common in today’s systems, e.g., the menu bar, trash can, stationery,
drag-and-drop, Undo, desktop menu, clipboard, interactive tutorials, and
exceptional graphics. For a thorough description of the Lisa user interface
see , , and .
Much of the Lisa interface was adopted by the Macintosh but there were
significant differences, particularly in their user models. The remainder of
this paper describes the Lisa’s document model, document save model,
and context switching management, highlighting how they differ from some of
today’s systems. For brevity, the following description assumes the
reader is familiar with one or more of today’s graphical desktop environments.
Document-centric user model
In the Macintosh document model , and that of Microsoft’s Windows , a
document is a typed disk file where the type determines the icon used to
represent it and the application to run, if any, when the disk file is
displayed in a window. These systems layer this model on
top of a “glass-box” computer model that exposes applications,
processes, and disk files in a way that cannot be ignored by users. The
Lisa model was based on the single concept of “document,” with
two forms of presentation, as icon or window, and the place where it
resides, a disk or diskette. It hides applications, processes, and disk
files from the user.
A user always began working on a document by selecting its icon and opening
it; there was no “Open...” command in any application’s File
menu (see Figure 1). New documents were created by selecting a stationery
pad and opening it; there was no “New” command in the File menu.
Opening stationery created a new document, duplicating the stationery’s
content, and automatically named it by adding the date to the stationery’s
name. It could then be opened immediately or renamed and/or filed before opening.
|Figure 1. Lisa Desktop. Note the lack of Open, New, and Quit commands|
When a document was opened, its shape changed from icon to window, leaving
only a place holder “shadow” at the icon’s location. When
the user “put away” the document, the window changed back to
its icon, replacing the shadow. If a user needed to temporarily interrupt
working on a document, it could be “set aside” on the desktop.
A set aside document was represented by its document icon, but behind the
scene it remained active, similar to a minimized window in today’s
systems, ready for quick access at a later time. Since users never saw both
document icon and window at the same time, a window was perceived as just
a form of presentation, not as an independent object with its own edit state.
Hiding processes and applications
Lisa users did not have to manage processes; there was no “Quit” command
in the File menu. When a window was put away or set aside, the Lisa activated
the next window or the desktop as appropriate. There was nothing left to indicate
the presence of a running process for the closed window, e.g., an orphaned menu
bar. Behind the scene, when the user opened a document, the Lisa would check to
see if the application was already running and, if so, ask the process to open
the document – most Lisa applications could manage several open documents. If
it could not, or if there was no process running, the Lisa would start a new
one. When a process’ last document was put away, rather than automatically
quitting the process, the Lisa would keep one application process running for
future use until its resources were needed to run something else. This approach
to process management removed the need to make processes visible to users
so that they could keep frequently used applications running in order to save time
when opening other documents of the same kind.
When a user activated a document by opening it, by clicking in its window, or by
picking it from the Desk menu, only that document window came forward. Some of
today’s windowing systems are process-based. If an application is designed
to handle multiple documents within a single process, activating a document
will bring forward all document windows managed by that process. This process-centric
operation can interfere with a user’s working with multiple documents
by potentially obscuring other windows of interest.
A Lisa user’s awareness of an application was limited to the existence of
its icon in the “Tools” folder. It was used only to verify the presence
of an application on a system and to update it via drag-and-drop replacement.
It could not be started directly by the user.
Hiding disk files
Lisa icons represented documents, folders, tools, and applications, not individual
disk files. Some icons, e.g., a folder, had no related diskfiles while
others, e.g., an application or document, had several. Grouping files in this
way reduced the number of icons a user saw. Users could not see or manipulate
individual disk files so they were never confused by the sudden appearance of a
temporary file, nor could they accidentally corrupt a document or applications by
removing, renaming, or discarding one disk file of a document’s set.
Persistent edits, save and revert
In the Lisa document save model, editing changes were persistent. The user
did not have to explicitly save changes to protect them from a crash or to
turn off the computer. Behind the scene, applications automatically saved changes
as needed to an invisible “suspend” file that was part of the document.
Users did specify whether changes were to be saved or discarded when a document
was put away. They could also do an explicit save after completing a coherent
set of changes. This gave a sense of task completion and set a
“save” state that enabled a user to easily remove subsequent changes
using the “Revert” command.
This approach to document saving was robust and eliminated the need for
precautionary saving and “Save changes?” dialogs. It also provided
the user with a simple versioning mechanism: the saved version and the
The Lisa preserved the current work context when the Lisa was powered off.
It recorded which documents, folders, and tools were on the desktop, the
location of each, and if open, the window’s location, size, and scroll
position. Similar actions were also performed when a diskette was ejected,
though just for those documents, folders, and tools that resided on the diskette.
When the user turned the Lisa on or reinserted a diskette, the icons and
windows reappeared as they were, much as some of today’s systems awaken from
the “sleep” state. However, to minimize startup time the Lisa did
not display a document’s actual content until a user indicated interest by
clicking within its window. The user could then resume editing, undo the last
change made during the previous session, or revert back to the last save
point that may have been days or even years ago.
The Lisa presented users with a user model and interface that was largely free
of many of the computer-related artifacts still found in today’s systems.
The result was a system that users could learn and use effectively in a very
short time. And it was fun to use.
Our thanks to Don Gentner and John Tang for their review and thoughtful comments.
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