The unavoidable tradeoff between flexibility and ease of use

The PC is extremely flexible. In Bill Gates’ words [Gates],
[s]itting at your PC, you can do your taxes, surf theWeb, write letters, e-mail friends, play
games, plan a business, buy a car, do your homework ... in fact, do whatever you want.
A network manager found 350 different software packages on the 1,000 PCs in his company [Jaffe].
Even more remarkable than the variety of applications that run on a PC is that the PC was not designed
with them in mind. The basic architecture of today’s PC is not much different from that of the early
Atari machines marketed to hobbyists. Yet spreadsheets and desktop publishing, the two “killer apps”
that propelled the PC to its current dominant status, could run on it. More recently, the rise of the Internet
in public consciousness can be dated to the mass distribution of the Mosaic browser. It penetrated
as widely and as rapidly as it did because it could be easily installed on millions of PCs that had been
acquired for other purposes. The idea of a universal information processing engine, which is what the
PC embodies, is extremely powerful.
Unfortunately, as Don Norman says (p. 181 of [Norman])
Computers are general-purpose devices, designed to do everything. As a result, they can’t
be optimized for any individual task.

That is one difficulty with the PC. Another, related, problem is that in the design of the PC, many
choices were made intentionally to make it as flexible and as user friendly as possible. (Yes, paradoxically,
it was the desire for ease of use that led to many of the problems the PC is derided for.) Users
have complete control over their machines, and can even modify the operating system at will, just by
clicking on an email attachment. This model makes any real security impossible. Further, it makes it
hard even for experienced computer experts to fix problems (cf. [Alsop]). Thus long-range ease of use
has been given up in favor of short-term convenience, in enabling users to modify their machines on
the spur of the moment. This is great if you care about rapid diffusion of the next Mosaic, but it leads
to frustration when things go wrong, as they often do. To provide stability, security, or transparency
requires limiting users’ flexibility.
A tradeoff between flexibility and ease of use is unavoidable. However, there is no single tradeoff
that is optimal for everyone. Don Norman argues that the PC was aimed at the “early adopters,” and that
its lack of success in penetrating about half of the households in the U.S. is a sign of its poor design.
Popular perception of the PC is certainly one of “infuriating complexity that makes us want to toss
our beloved PCs out the window about, oh, once an hour” [Levy]. The success of the iMac is another
sign that consumers do value simplicity. Norman argues that information appliances can and should be
designed for the mass market. Proper design of simple interfaces, appropriate when a restricted set of
tasks is to be enabled, does make this possible.
The problem, as was explained earlier, is that we should not be thinking just of individual information
appliances. Those can be made to appear simple through careful design, and in particular by
limiting their functionality. We have to be concerned with the whole system, which is likely to be
complex. Further, there is no single tradeoff of flexibility versus ease of use that is optimal for everyone.
There is not even a single tradeoff that is likely to be optimal for any individual for long. A
person learning a new system can usually handle progressively more features. Thus we cannot hope
to design information appliances to a single standard. Norman cites the example of the evolution of
radio receivers as models of how computers should change. However, there is a substantial difference
between radios and computers. We need a much greater variety of computers than of radios. Further,
in the networked environment, the full range of information appliances with varying capabilities will
have to interoperate.
To appreciate the wide range of computing that we have, and are likely to have in the future,
consider open source software. It is often touted as a proof that a viable competitor to Microsoft’s

Windows can arise. Yet it seems that that the main lesson to be drawn from the success of Linux and
Apache is different. These systems are built by experts to be used by experts. There are many people
(although a tiny fraction of the whole population) who know what regular expressions are, and can
use text commands to execute programs much faster than a graphical user interface would let them.
They also tend to be in charge of important resources such as Web servers, and appreciate (and use
effectively) the flexibility that access to source code provides. Apache and Linux are ideal for them.
They are not satisfied with the black-box software from commercial vendors. On the other hand, it is
doubtful whether those among them who contribute to the code, as opposed to just using it, have the
interest in creating the easy to use but much less flexible interface that would appeal to a wider market.
That is the province of Microsoft, Apple, and other software companies. (There might be a business
opportunity for companies to put simple interfaces on top of Linux for the mass market, though.) These
expert users do not account for a large fraction of desktop computers, but do control a a large share of
computing budgets. They form a substantial market for computers where flexibility is dominant, even
at the cost of ease of use.
At the other extreme, about half of the households in the U.S. still do not have any computer, and
often this is because of the perceived difficulty of using current PCs. Further, there are millions of
VCRs whose clocks flash 12:00. The owners of these VCRs are ignoring the ability to program videotaping
on their devices. This is the standard response of consumers to features that do not provide
enough value compared to the hassle of using them. What it means is that information appliances will
have to be extremely attractive and easy to use to gain wide acceptance. Further, the full range of users,
from the computer experts using open source systems, to the totally non-technical folks, will have to
operate within the same communications infrastructure.