incredibly easy to use desktop with a
bitmapped display; the DEC VAX VMS,
which was amazingly stable and retained previous versions of files for fast
recovery; VisiCalc, the first automated
spreadsheet, which made easy accounting available to anyone; Lotus 1-2-3, a
successor of VisiCalc, which enabled
arbitrary formulas in cells and opened
a new programming paradigm; and Microsoft Word, which made professional
document formatting easy and eventually effectively banished most other
word processors from the market.
Recent examples include the iPhone
and Android operating systems, which
allow customizable access to millions (literally) of downloadable apps.
Among the apps themselves some have
attained high delight ratings; for example, many airlines, publishers, and
newspapers offer apps that give direct
access to their content via a mobile device. Some apps give users access to networks where data from many others is
aggregated to give the user something
that saves a lot of time and anxiety. For
example, Amazon created the Kindle
reader service that enables users to purchase e-books from the Amazon store
and begin reading them instantly from
any device with a Kindle app. Google
and Apple maps use location information from smartphones to detect traffic
congestion, overlay it on street maps,
and propose alternate routes around
congested areas. Blizzard Entertainment accumulated as many as 10 million subscribers to its World of War-craft online game because of its rich
complexity and realistic graphics. Uber
allows users to hail rides whose drivers come to their exact location within minutes. In each case, customers
found they could do previously impossible things with the app than without,
much more than they expected.
The interesting thing about these
examples is that many failed important
ISO metrics such as portability, speed,
efficiency, or reliability. Yet people ignored those shortcomings and became
avid and loyal subscribers to the software developer.
Software developers are banking on
new delights as artificial intelligence
technology matures. Many people are
looking forward to driverless cars, per-
sonal assistants that know your daily
routines and keep you from becoming
forgetful, and virtual reality tools that
allow you to tour distant places, train
risk-free for a new skill or environment,
or access new kinds of entertainment.
But delight is ephemeral if based on
the software itself: Having mastered the
new environment, the user will expand
horizons and expect more. Few would
find the original Unix, Macintosh, VMS,
VisiCalc, or Word to be delightful today.
Software producers now invest considerable effort into anticipating what will
delight their users in the future. Their
question has to be: Will we be able to
provide delightful surprises for customers with growing expectations?
I have argued that software quality
evaluation has transformed significantly from code-level measures of the
1970s to user-level assessments today.
I proposed six levels at which users assess software quality. The levels reflect
different degrees of emphasis on user
satisfaction. Program correctness is essential but is limited to quality at the
first level. The highest level—delight—
arises in the context of the relationship
between the customer and performer.
The delighted customer will say that
the performer has taken the trouble to
understand the customer’s work and
business, is available to help with problems and to seize opportunities, may
share some risks on new ventures, and
generally cares for the customer. Software producers today look to designs
and services that produce genuine delight. When they succeed we witness
new waves of killer apps.
1. Blekinge Institute of Technology. Software quality
models and philosophies; http://bit.ly/1VXv15L.
2. Boehm, B., Brown, J., Kaspar, H., Lipow, M., McLeod,
G., and Merritt, M. Characteristics of Software Quality.
North Holland, 1978.
3. Howard, M. and Lipner, S. The Security Development
Lifecycle SDL. Microsoft Press, 2006.
4. International Standards Organization. ISO 9126 on
software quality. 1993 (standard was updated in 2001
and 2011); http://bit.ly/1ZOpIEY.
5. McCall, J., Richards, P., and Walters, G. Factors in
software quality. National Technical Information
Service 1, 2, 3 (1977).
6. Shewart, W.A. Economic Quality Control of
Manufactured Products. Van Nostrand, 1931.
Peter J. Denning ( email@example.com) is Distinguished
Professor of Computer Science and Director of the
Cebrowski Institute for information innovation at the
Naval Postgraduate School in Monterey, CA, is Editor
of ACM Ubiquity, and is a past president of ACM.
The author’s views expressed here are not necessarily
those of his employer or the U.S. federal government.
Copyright held by author.
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