Using Guidelines to Assess Navigation Models of Web Applications

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Using Guidelines to Assess Navigation Models of
Web Applications

• Joseph Xiong, Christelle Farenc, Marco Winckler
• xiong, farenc, winckler_at_irit.fr
• Supervisor Christelle Farenc
• LIIHS - Logiciels Interactifs et Interaction
  Homme-Système
• Institut de Recherche en Informatique de Toulouse

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Evaluating Usability According to Guidelines
Conformity

• Existing Approaches
• Usability Inspection Methods (heuristic
  evaluation, cognitive walkthroughs, etc.)
• Automated tools (ex. Bobby http//bobby.watchfire.
  com)
• Prototype-based evaluations
• Our approach applying ergonomic rules to a
  model in the design activities
• (context) Navigation in Web applications

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Plan

• Taxonomy of ergonomic rules concerning navigation
• Application of ergonomic rules to a navigation
  model
• Rules interpretation
• Conclusion and Perspectives

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Examples of ergonomic rules

• Ensure that all pages are accessible
• Ensure that image maps are accessible to
  vision-impaired users
• Provide persistent links to the home page and
  high-level site categories
• (source EvalWeb Project Scapin et al. 99)

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Taxonomy of ergonomic rules

• Step in the life cycle
• Design
• Implementation
• Evaluation
• Level of Automation
• Integrated
• Automatic
• Semi-automatic
• Non-automatic (manual)
• Not verifiable

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Taxonomy examples

• Level of Automation / Step in the life cycle
• Ensure that all pages are accessible
• Design Automatic
• Implementation Automatic
• Evaluation Automatic
• Ensure that image maps are accessible to
  vision-impaired users
• Design Not Verifiable
• Implementation (may be) Integrated
• Evaluation (may be) Automatic

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Navigation Model StateWebCharts Winckler 2004

• Spider Web Project (http//liihs.irit.fr/winckler
  /projects/spider/spider_intro.html)

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Applying rules to a navigation model

• StateWebCharts (SWC) Winckler 04
• SWC
• StateCharts Harel 87 extensions

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Rules Interpretation

• Translation of ergonomic rules into elements of
  the model (SWC)
• Rules are defined by
• Element
• Constraint
• Action if the rule is respected (IF)
• Action if the rule is not respected (ELSE)
• Rule diagram

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Interpretation example

• Example
• Rule Ensure that all pages are accessible
• Interpretation For all pages, it exists one
  or more link pointing to these pages
• Rule writing

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Conclusion and Perspectives

• Taxonomy of ergonomic rules
• Approach for applying rules to a model of the
  system
• Limits
• Interpretation
• Navigation model

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Conclusion and Perspectives

• Perspectives
• Ergonomic aspects
• Classify the ergonomic rules according to
  ergonomic criteria
• Weighting rules
• Tool supporting this method
• Currently in development

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Thanks for your attention
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StateWebCharts
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Taxonomy of ergonomic rules lt
Design
Implementation
Evaluation
The "O" Life Cycle of a Web Application Scapin
et al. 00