Usability-and-the-Web

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					                                                                             Briefing-15                                                                                      Briefing-15


                    Usability and the Web                                                                            Usability and the Web
                 UKOLN: Supporting The Cultural Heritage Sector                                            UKOLN: Supporting The Cultural Heritage Sector

Background                                                                                        Background
Usability refers to a quality attribute that assesses how easy user interfaces are to use.        Usability refers to a quality attribute that assesses how easy user interfaces are to use.
The term is also used to refer to a number of techniques and methods for improving                The term is also used to refer to a number of techniques and methods for improving
usability during the various stages of design and development.                                    usability during the various stages of design and development.

What Does Usability Include?                                                                      What Does Usability Include?
Usability can be separated into several components [1] such as:                                   Usability can be separated into several components, such as: [1]
    Learnability: How easy it is to get to grips with an unfamiliar interface?                        Learnability how easy it is to get to grips with an unfamiliar interface
    Efficiency: How quickly an experienced user can perform a given task?                             Efficiency how quickly an experienced user can perform a given task
    Memorability: Once familiar with an interface, is it easily forgettable?                          Memorability once familiar with an interface, is it easily forgettable?
    Errors: How easy is it to make mistakes/recover from mistakes?                                    Errors how easy is it to make mistakes/recover from mistakes?
    Satisfaction: Is the design enjoyable to use?                                                     Satisfaction is the design enjoyable to use?
These characteristics are all useful metrics, although the importance of each one                 These characteristics are all useful metrics, although the importance of each one
depends on the expected uses of the interface in question. In some circumstances, such            depends on the expected uses of the interface in question. In some circumstances, such
as software designed for a telephone switchboard operator, the time it takes for a skilled        as software designed for a telephone switchboard operator, the time it takes for a skilled
user to complete a task is rather more important than learnability or satisfaction. For an        user to complete a task is rather more important than learnability or satisfaction. For an
occasional web user, a web site’s designers may wish to focus principally on providing            occasional web user, a web site’s designers may wish to focus principally on providing
a site that is learnable, supports the user, and is enjoyable to use. Designing a usable site     a site that is learnable, supports the user, and is enjoyable to use. Designing a usable site
therefore requires a designer to learn about the needs of the site’s intended users, and to       therefore requires a designer to learn about the needs of the site’s intended users, and to
test that their design meets the criteria mentioned above.                                        test that their design meets the criteria mentioned above.

Why Does Usability Matter?                                                                        Why Does Usability Matter?
More attention is paid to accessibility than to usability in legislation, perhaps because         More attention is paid to accessibility than to usability in legislation, perhaps because
accessibility is perceived as a clearly defined set of guidelines, whilst usability itself is a   accessibility is perceived as a clearly defined set of guidelines, whilst usability itself is a
large and rather nebulous set of ideas and techniques. However, a Web site can easily             large and rather nebulous set of ideas and techniques. However, a Web site can easily
pass accessibility certification, and yet have low usability; accessibility is to usability       pass accessibility certification, and yet have low usability; accessibility is to usability
what legible handwriting is to authorship. Interfaces with low usability are often                what legible handwriting is to authorship. Interfaces with low usability are often
frustrating, causing mistakes to be made, time to be wasted, and perhaps impede the               frustrating, causing mistakes to be made, time to be wasted, and perhaps impede the
user from successfully reaching their intended goal at all. Web sites with low usability          user from successfully reaching their intended goal at all. Web sites with low usability
will not attract or retain a large audience, since if a site is perceived as too difficult to     will not attract or retain a large audience, since if a site is perceived as too difficult to
use, visitors will simply prefer to take their business elsewhere.                                use, visitors will simply prefer to take their business elsewhere.

This document is available at:                                                                    This document is available at:
<http://www.ukoln.ac.uk/cultural-heritage/documents/briefing-15/>                                 <h ttp://www.ukoln.ac.uk/cultural-heritage/documents/briefing-15/>
Usability Testing                                                                                 Usability Testing
User testing is traditionally an expensive and complicated business. Fortunately, modern          User testing is traditionally an expensive and complicated business. Fortunately, modern
discount (‘quick and dirty’) methods have changed this, so that it is now possible to             discount (‘quick and dirty’) methods have changed this, so that it is now possible to
quickly test the usability of a web site at any stage in its development. This process, of        quickly test the usability of a web site at any stage in its development. This process, of
designing with the user in mind at all times, is known as user-centred design. At the             designing with the user in mind at all times, is known as user-centred design. At the
earliest stages, an interface may be tested using paper prototypes or simple mockups of           earliest stages, an interface may be tested using paper prototypes or simple mockups of
the design. It is advisable to test early and often, to ensure that potential problems with a     the design. It is advisable to test early and often, to ensure that potential problems with a
design are caught early enough to solve cheaply and easily. However, completed Web                design are caught early enough to solve cheaply and easily. However, completed Web
sites also benefit from usability testing, since many such problems are easily solved.            sites also benefit from usability testing, since many such problems are easily solved.
User testing can be as simple as asking a group of users, chosen as representative of the         User testing can be as simple as asking a group of users, chosen as representative of the
expected user demographic, to perform several representative tasks using the Web site.            expected user demographic, to perform several representative tasks using the Web site.
This often reveals domain-specific problems, such as vocabulary or language that is not           This often reveals domain-specific problems, such as vocabulary or language that is not
commonly used by that group of users. Sometimes user testing can be difficult or                  commonly used by that group of users. Sometimes user testing can be difficult or
expensive, so discount techniques such as heuristic evaluation [2], where evaluators              expensive, so discount techniques such as heuristic evaluation [2], where evaluators
compare the interface with a list of recommended rules of thumb, may be used. Other               compare the interface with a list of recommended rules of thumb, may be used. Other
discount techniques include cognitive walkthrough in which an evaluator role-plays                discount techniques include cognitive walkthrough in which an evaluator role-plays
the part of a user trying to complete a task. These techniques may be applied to                  the part of a user trying to complete a task. These techniques may be applied to
functional interfaces, to paper prototypes, or other mockups of the interface.                    functional interfaces, to paper prototypes, or other mockups of the interface.
A common method to help designers is the development of user personas, written                    A common method to help designers is the development of user personas, written
profiles of fictitious individuals who are designed to be representative of the site’s            profiles of fictitious individuals who are designed to be representative of the site’s
intended users. These individuals’ requirements are then used to inform the design                intended users. These individuals’ requirements are then used to inform the design
process and to guide the design process.                                                          process and to guide the design process.

Conclusions                                                                                       Conclusions
Considering the usability of a web site not only helps users, but also tends to improve           Considering the usability of a web site not only helps users, but also tends to improve
the popularity of the site in general. Visitors are likely to get a better impression from        the popularity of the site in general. Visitors are likely to get a better impression from
usable sites. Quick and simple techniques such as heuristic evaluation can be used to             usable sites. Quick and simple techniques such as heuristic evaluation can be used to
find usability problems; frequent testing of a developing design is ideal, since problems         find usability problems; frequent testing of a developing design is ideal, since problems
can be found and solved early on. Several methods of usability testing can be used to             can be found and solved early on. Several methods of usability testing can be used to
expose different types of usability problems.                                                     expose different types of usability problems.

References And Further Information                                                                References And Further Information
1.    Usability 101: Introduction to Usability, J. Nielsen,                                       1.    Usability 101: Introduction to Usability, J. Nielsen,
      <http://hcibib.org/tcuid/chap-4.html>                                                             <http://hcibib.org/tcuid/chap-4.html>
2.    Heuristic Evaluation, J. Nielsen, <http://portal.acm.org/citation.cfm?id=142869>            2.    Heuristic Evaluation, J. Nielsen, <http://portal.acm.org/citation.cfm?id=142869>

     Ten Usability Heuristics, J. Nielsen,                                                            Ten Usability Heuristics, J. Nielsen,
      <http://www.useit.com/papers/heuristic/heuristic_list.html>                                       <http://www.useit.com/papers/heuristic/heuristic_list.html>
     Personas: Matching a design to the users’ goals,                                                 Personas: Matching a design to the users’ goals,
      <http://www.uie.com/articles/personas/>                                                           <http://www.uie.com/articles/personas/>

Produced by UKOLN: a national centre of expertise in digital information management    Jul 2008   Produced by UKOLN: a national centre of expertise in digital information management   Jul 2008
For further information see <http://www.ukoln.ac.uk/>                                             For further information see <http://www.ukoln.ac.uk/>

				
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