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Section 4 - Usability Methods In
Requirements Analysis of Web-based Information
Systems
When discussing users' requirements in the
context of a Web-based information system, usability is
often mentioned. "Usability" has been defined as a
measure of "the ease with which users can learn or use a
system, its safety, effectiveness, and efficiency, and
users' attitude toward it."34 At the requirements analysis
stage, usability methods can be used to help gather
information about users. In his article Developing
usable Web sites - a review and model, Daniel Cunliffe
offers a useful summary of some of these methods that
can be applied to a WIS requirements analysis:
competitive analysis, scenarios, inspection methods, log
analysis, and on-line questionnaires.
Competitive analysis - This type of analysis
is easy to conduct since it involves comparing Web sites
that are publicly accessible from the Internet and which
offer similar products or services. It does not require
a large financial investment, but it may require large
sunk costs in terms of time spent comparing Web sites
and identifying their best features. In order to make
sure that the users' perspectives are represented, it is
best to have real users conduct the competitive
analysis. This is based on the assumption that genuine
users are more inclined to identify what features will
best meet their requirements. However, the level of
effectiveness of such a technique also depends on the
users' level of familiarity with using the Web. In order
to appreciate the effectiveness of the features
encountered on these Web sites, users would have to have
had experience conducting business on the Web in the
past. At the end of competitive analysis, the developers
should have a list of desirable features for the site.
Scenarios -
Conducting a competitive analysis with real users is
ideal. However, as mentioned earlier, users of a
Web-based information system often are unreachable or
unknown. Scenario analysis can help developers to
identify users requirements by using people - "proxy
users" - who are considered to have similar attributes
to the real users. Scenarios are used in order to
provide some guidance to the proxy users when conducting
user testing in order to control for the differences
that may exist between the "proxy users" and the "real
users". The scenarios are developed through
brainstorming or focus group sessions involving the
system stakeholders and the developers. To create more
realistic scenarios, users can be involved in this
process as well. Scenario analysis is helpful to
generate ideas and users requirements.
Inspection methods - Inspection methods
can be used throughout the development process. In a WIS
development process, inspection methods can be used in
conjunction with prototyping and requirements analysis
in an iterative manner. Inspection methods involve "a
systematic (but not necessarily exhaustive) comparison
of an interface against a pre-determined set of criteria
or guidelines (which may be specified at higher or lower
levels of abstraction)."35 Inspection methods does not
require a high financial investment, but may be time
consuming since the evaluator will have to inspect each
page of the prototype and check it against identified
requirements. The results of inspection methods are a
set of revisions or modifications that need to be made
to users requirements.
On-line questionnaires - They are
effective tools to collect information about user
behaviors. However, Cunliffe identifies a major concern
with on-line questionnaires. It "is the self-selecting
nature of the sample, raising concern as to whether or
not the users who have answered the questionnaire are
typical users ."36 Another drawback with on-line
questionnaires is that the organization may not have the
infrastructure in place to survey their customers.
However, and despite these concerns, on-line
questionnaires are tools of the next generation. They
offer enormous opportunities in terms of allowing
organizations to reach their global customers in a
cost-effective manner. On-line questionnaires are used
in the evaluation of on-line prototypes, and can help to
identify users behaviors.
Research in the development process of Web-based
information systems has concentrated on the design and
implementation phases of the process. And although
usability methods have been mostly studied in that
context, I believe they can also be powerful tools at
the requirements analysis stage. They can offer insight
into WIS users and provide opportunities to better
identify users requirements.
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