WEB USABILITY

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WEB USABILITY

• Group 2
• Asan, Günalp
• Durdak, Yavuz
• Eken,Nazli
• Erdogdu ,Özen

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USABILITY

• ISO official definition
• The effectiveness, efficiency, and satisfaction
  with which specified users achieve specified
  goals in particular environments.

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• Nielsen was able to conclude
• "On the Web, if a site is difficult to use, most
  people will leave."

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What is Web Usability?

• Web site usability is not just about making sure
  everything on the site works, but how quickly and
  easily visitors are able to make use of the site

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General issues that impact web usability

• Speed
• Searching
• Personalization
• Navigation
• ..etc..

• Advertising
• Animation
• Graphics
• Linking
• Multimedia

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Computer Networks and ISDN systems 29(1997)
Usability studies and designing navigational
aids for the WWWD.Bachiochi
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• This paper describes
• how usability testing was used to validate
  design recommendations.

• The results show a need for navigational aids
  that are related to the particular Website and
  located beneath the Browser buttons.

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TEST

• A series of questions related to the Website(45
  pages).
• Time to locate and answer each question was
  recorded.
• Resultsevalutors wanted navigation buttons fixed
  at the top, scrolling to button locations is not
  wanted, home is a very important concept, users
  do not read blocks of text, react to links, The
  Local Navigation buttons were very confusing.

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• - To efficiently find information, users should
  not have to
• make more than 4 page changes,
• take longer than 60 seconds to find
  information.

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Critical factors for the aesthetic fidelity of
web pages empirical studies with professional
webdesigners and users -Su-e Park, Dongsung
Choi, Jinwoo Kim- HCI Lab, Yonsei University
Interacting with Computers 16 (2004) 351376
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The main goal

• to identify critical factors that are closely
  related to the aesthetic fidelity of web pages,
  which is defined as the degree to which users
  feel the target impressions intended by
  designers.

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Studies conducted

• exploratory study with web users
• experiment with professional web designers
• online survey with web users

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Three candidate factors

• reliability of aesthetic dimensions
• variability of user perceptions
• appropriateness of visual design.

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Result
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Improving Web interaction on small displaysMatt
Jones _1, Gary Marsden 1, Norliza Mohd-Nasir 1,
Kevin Boone 1, George Buchanan 1Interaction
Design Centre, School of Computing Science,
Middlesex University, London, UK

• A study into the usability impact of small
  displays for retrieval tasks

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• Objectives
• To quantify the effect of small display space on
  Web-based task completion
• To gain qualitative impressions on how reduced
  displays might affect the ways users approach
  Web-based information retrieval

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• The Experiment
• The volunteers were asked to use Web based
  information system to complete two tasks
• One group accessed the site using a browser with
  large screen
• The other group used the same site with the
  small screen

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• Results
• The success rates in completing the tasks by the
  two user groups were compared.
• (The overall probability of a question being
  answered correctly .)
• The large screen group answered twice as many
  questions correctly than the small screen group

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• Design Lessons
• Provide direct access
• Structure information to provide focused
  navigation
• Reduce scrolling

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The effect of text and background colour on
visual search of Web pagesJonathan Ling, Paul
van SchaikPsychology Section, School of Social
Sciences, University of Teesside, Middlesbrough
TS1 3BA, UK

• The effect of the combination of text and
  background color on visual search performance and
  subjective preference

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• The Experiment
• The independent variable colour combination of
  text colour and background colour in navigation
  frames.
• The dependent variables
• four performance measures (number of hits, number
  of correct rejections, reaction time for hits,
  reaction time for correct rejections)
• two subjective measures (an aggregate rating of
  display quality and an overall preference rating)

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• Analysis of variance (ANOVA) was used to assess
  the effect of colour in terms of differences in
  mean scores
• Correlation was employed to assess the
  association between performance measures

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• Results
• Colour combination had an effect on both
  accuracy (hits and correct rejections) and speed
  (reaction time for hits and correct rejections)
  of visual search.
• Combination had an effect on preference and
  perceived display quality.

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The effects of screen ratio and order on
information retrieval in web pagesPaul van
Schaik, Jonathan LingPsychology Section, School
of Social Sciences, University of Teesside,
Middlesbrough, TS1 3BA, UK

• Typical Web pages divide the screen into a menu
  area for navigation and a content area to display
  information.
• The Golden Section can be applied to decide on
  the proportion of these two areas on the screen
  when designing this type of page

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Screen ratio Percentages of screen width
occupied by the navigation area (on the left) and
the content area (on the right)
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• The Experiment
• Participants were asked questions based on
  information available on the web sites.
• Answers to the questions were one (for half of
  the questions) or two (for other half of the
  questions) links away from the home page.
• Two sets of rating questions (to rate their
  satisfaction with display quality in terms of the
  width of the navigation area, content area e.t.c)
  were also presented to participants.

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• Results
• Analysis of variance (ANOVA)
• and simple effect tests were conducted to test
  the effects of screen ratio and order on outcome
  measures.
• An effect of screen ratio on task performance
  (both speed and efficiency) and subjective
  measures (display quality and preferred screen
• width) was found.

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Pushing back Evaluating a New Behavior for the
Back and Forward Buttons in Web Browsers

• Back and Forward Buttons are CRUCIAL for web
  usability!

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Pushing back Evaluating a New Behavior for the
Back and Forward Buttons in Web Browsers

• This article discusses compares the temporal
  approach to stack-based behavior of Back
  Forward buttons.
• Temporal Maintains a
  complete
• Back Forward list of
  previously
• Buttons visited
  pages

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Stack-based Classical, only
you can Back Forward visit the
last previous Buttons
back and forward
pages
Pushing back Evaluating a New Behavior for the
Back and Forward Buttons in Web Browsers
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Effects of Training and Representational
Characteristics in Icon Design

• ICONS The components mostly
  attracting human perception
• And predominantly designed artistic!!

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Effects of Training and Representational
Characteristics in Icon Design

• This article addresses and issues of what should
  be depicted, given the function it should
  represent,
• And, how training affects users when using an
  iconic interface

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Concepts for Improved Visualization of Web Link
Attributes

• Links on Internet may bring the Multiplier Effect
  to reach information!!
• Links The key for Internet
  surfing, if truly designed for
  users

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Concepts for Improved Visualization of Web Link
Attributes

• Current web browsers make it hard to predict what
  will happen if a link is followed users get
  different info. then expected, a new un related
  window may be opened, a download starts or the
  destination objective is not available!!!

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Concepts for Improved Visualization of Web Link
Attributes

• But it is usually possible to obtain hyperlink
  info.!!
• In this paper several types of Web hyperlink
  info. are listed,
• Potential methods to present these facts are
  compared
• A prototype implementation of the proposed
  concept is presented

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Improving Web Usability with the Link Lens

• Again we consider an article about world wide web
  links
• A number of factors may influence Web Users
  choice of links to follow

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Improving Web Usability with the Link Lens

• How do users deal with the problem of having to
  make decisions when the information about the
  links is insufficient??
• This paper conducts an investigation of how users
  make link selections

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Improving Web Usability with the Link Lens

• An enhanced link user interface designed to make
  such decisions easier productive for all users
  offered

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A Psychological Investigation of Long Retrieval
Times on the World Wide Web

• With the rapid uptake of the WWW, even those
  pages classed as the best of the web are not
  immune to large download latencies

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A Psychological Investigation of Long Retrieval
Times on the World Wide Web

• This paper investigates whether the latency
  between requesting a page and receiving it
  influence user perceptions of the page
• Interestingly, pages retrieved faster were found
  more interesting than their slower counterparts

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Web Site UsabilityMARK PEARROW
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What is Usability?

• the practice of designing products so that
  users can perform required use, operation,
  service, and supportive tasks with a minimum of
  stress and a maximum of efficiency. (Woodson,
  1981)

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Benefits of usability

• Improved system design means happier clients
• Happier clients mean positive perception of your
  organization
• More successful transactions means higher
  performance
• Reduced training costs

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Costs of poor design

• Negative perception of organization
• Failed transactions
• When a web based system fails to fill a clients
  need they pursue other costlier alternatives
  (phone support, phone ordering, etc.)

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UCD The Philosophy

• User Centered Design means designing the system
  to help the user
• UCD means getting feedback from real users early
  and often throughout design process

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3 Principles of UCD

• Early focus on users and tasks
• Empirical measurement of product usage
• Iterative design whereby a product is designed,
  modified, and tested repeatedly

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UCD Methodology

• Comprehensive usability plan
• Randomly selected, representative participants
• Integrating participant feedback throughout
  entire design lifecycle
• Commitment to usability at every level of your
  organization

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Goals of UCD

• Ease of learning
• Recall
• Productivity
• Minimal error rates
• High user satisfaction

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UCD Questions

• What do you want the product to do for you?
• In what sort of environment will you be using the
  product?
• What are your priorities when using the software?
  For example, which functions will you use most
  often?
• How are you doing these tasks today?
• What do you like and dislike about the way you've
  been getting your tasks done?

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Designer-centered Design

• Very common, usually fails
• Designers are not users, and systems designed for
  the designers are not useable by users

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Distinct user categories

• Many types of users may use your design
• Pay attention to these subclasses of users and
  identify their unique traits
• Use a matrix design to equally represent all of
  the groups

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Human Factors Cultural Differences

• The Web is Worldwide
• Meanings of icons, sayings, gestures, etc. arent
  usually global
• A check mark is the symbol for negation
• The color red indicates happiness
• The symbol for OK is lewd
• References to literary characters dont fly
• many other differences

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Understanding the User

• How do your users work?
• task analysis, interviews, observation
• How do your users interact with current
  applications/traditional tools?
• Field study allows you to understand current
  workflow

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Top Web User Complaints
Source http//www.cc.gatech.edu/gvu/user_surveys/
survey-1998-10/graphs/use/q11.htm
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Usability Toolbox

• Inquiry
• Inspection
• Testing

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Inquiry

• Contextual Inquiry
• Ethnographic Study / Field
• Observation
• Interviews and Focus Groups
• Surveys

• Questionnaires
• Journaled Sessions
• Self-reporting Logs
• Screen Snapshots

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Inspection

• Heuristic evaluation
• Cognitive Walkthroughs
• Formal Usability Inspections
• Pluralistic Walkthroughs

• Feature Inspection
• Consistency Inspection
• Standards Inspection
• Guideline checklists

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Testing

• General concepts
• Thinking Aloud protocol
• Co-discovery method
• Question asking protocol
• Performance measurement

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Feedback

• Clear and consistent feedback is crucial for
  usable systems
• A lack of feedback can result in errors, multiple
  form submissions, or being lost
• Make system status visible at all times

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Principles for well-designed sites

• Simplicity (Parsimony)
• Support
• Familiarity
• Obviousness
• Encouragement
• Satisfaction

• Availability
• Safety
• Versatility
• Personalization
• Affinity

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Top Ten Mistakes of Web Sites

• Breaking/Slowing down Back button
• Opening new browser windows
• Non-standard GUI use
• Lack of Biographies
• Lack of archives
• Moving pages to new URLs

• Headlines that make no sense out of context
• Jumping on latest buzzword
• Slow server response time
• Anything that looks like advertising

From http//www.useit.com/alertbox/990530.html
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Top Web User Complaints
Source http//www.cc.gatech.edu/gvu/user_surveys/
survey-1998-10/graphs/use/q11.htm
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• THANK YOU.