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Taking computers to task, Gibb, W.W., Scientific
American, July, 82-89 (1997).
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Are we really doing the best that we can do with user interfaces?
Gibbs (1997) provided a strong argument in favor of enhancing usability
programs in industry. He noted that even though businesses generally invest
in computers to lower their costs and to increase their profits, studies
show that over the past 30 years annual productivity growth has fallen.
For all the useful things computers do, they do not seem to have substantially
improved overall productivity.
He suggests that maybe the way that computer systems are designed does
not improve the efficiency and quality of most work. Frequently, when
new systems are installed they actually
increase costs. Much of the time saved by automation is frittered away
by software that is slow and inefficient, unnecessarily difficult and
unpredictable.
In 1997, business personal computers (PCs) reportedly cost about $3,000
each, which is about $1,000 a year over the average life span of a typical
computer. However, related costs per computer are about $12,000:
- technicians to keep the computers and networks working - $1,170
- linking to a network and required basic software - $1,730
- training and technical support - $3,510
- employees wasting time (surfing, customizing, futzing) - $5,590
This makes the total annual cost, not $1,000, but closer to $13,000.
In addition, because many systems are so difficult to use (i.e., they
have poor user interfaces), employees can take up to 10% of their time
helping co-workers with computer problems. This increases the annual cost
of a PC up to $23,500.
Studies show that the factor most closely linked to these support costs
is the extent to which the user interface matches the way users think
and work. Even though designing high quality user interfaces is difficult,
effectively applying usability research could make computer systems dramatically
more productive, easier to use and cheaper to support.
For example, usability specialists helped improve the overall productivity
of the New York Stock Exchange. They participated in upgrading the four
primary computer systems used on the trading
floor. The designers developed prototypes, conducted usability tests and
made many revisions. Overall productivity increased dramatically. The
workload capacity doubled (they can now handle over 2 billion shares a
day), and the error rates fell by a factor of 10.
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From Sufficient to Efficient Usage: An Analysis
of Strategic Knowledge, Bhavnani, S.K. and John, B.E., Proceedings
of CHI’97, 91-98 (1997).
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Can good usability design guarantee efficient usage of computer systems?
Bhavnani and John (1997) observed that many veteran employees do not
use computer tools efficiently even after formal training and many years
of experience. Adequate design seems to lead to sufficient usage, but
it does not guarantee efficient usage. It appears that efficient usage
requires knowledge that is beyond the design of the system itself.
One way to help ensure efficiency is to effectively use "aggregation."
Aggregation is the ability to group disjoint elements, and then manipulate
the group with an appropriate operator. For example, selecting 10 items
in a folder and then deleting them all by pressing the delete key. Or
selecting several elements in a graphic and applying a color or filter
to all elements simultaneously. Even though aggregation can be a powerful
mechanism for helping to ensure efficiency, studies suggest that even
experienced users have trouble effectively applying aggregation.
The issue of efficiency seems to arise when there is more than one way
of performing tasks, particularly complex tasks. To take full advantage
of aggregation designers should:
- Provide few, but efficient, ways to perform,
- Design user interfaces (and required training) to include strategies
for the effective use of aggregation,
- Users should be encouraged to find and use more effective aggregation
strategies, and
- Systems should detect when aggregation is not being used, and suggest
appropriate aggregation strategies.
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