CSCI 102 Intro to IT B Autumn 2002 Introduction to HCI Lecturer Gene Awyzio (02)

Overview Designing for maximum usability is the goal of design History of interactive system design provides paradigms for usable designs Principles of usability are more general means of understanding usability

Introduction Concerns –How can an interactive system be developed to ensure its usability? –How can the usability of an interactive system be demonstrated or measured? Approaches –Paradigms for usability examples of successful interactive techniques –Principles for usability theoretically driven from psychological, computational and sociological knowledge

Historical perspective on interactive system design Time-sharing –40s and 50s – explosive technological growth –60s – need to channel the power J.C.R. Licklider at ARPA single computer supporting multiple users Video Display Units more suitable medium than paper –1962 – Sutherland's Sketchpad –Computers for visualizing and manipulating data –One person's contribution could drastically change the history of computing Time-sharing –40s and 50s – explosive technological growth –60s – need to channel the power J.C.R. Licklider at ARPA single computer supporting multiple users Video Display Units more suitable medium than paper –1962 – Sutherland's Sketchpad –Computers for visualizing and manipulating data –One person's contribution could drastically change the history of computing X _ X _

Principles to Support Usability A structured presentation of general principles to apply during design of an interactive system. Learnability –the ease with which new users can begin effective interaction and achieve maximal performance Flexibility –the multiplicity of ways the user and system exchange information Robustness –the level of support provided the user in determining successful achievement and assessment of goal-directed behaviour A structured presentation of general principles to apply during design of an interactive system. Learnability –the ease with which new users can begin effective interaction and achieve maximal performance Flexibility –the multiplicity of ways the user and system exchange information Robustness –the level of support provided the user in determining successful achievement and assessment of goal-directed behaviour X _ X _

Common Interface Design Mistakes Controls. Questions Visual elements Use of colour Terminology Error messages Tabbed Dialogs Metaphors Globalisation Controls. Questions Visual elements Use of colour Terminology Error messages Tabbed Dialogs Metaphors Globalisation X _ X _

Controls Controls represent the means by which the user communicates with the application The quality of the communication depends on two aspects of the controls: –The appropriateness of the control for the task –The consistency of the rules under which the control operates. Select the wrong tool for the job, or change the rules under which the tool operates, and you will create problems for your users. Here are some examples... Controls represent the means by which the user communicates with the application The quality of the communication depends on two aspects of the controls: –The appropriateness of the control for the task –The consistency of the rules under which the control operates. Select the wrong tool for the job, or change the rules under which the tool operates, and you will create problems for your users. Here are some examples... X _ X _

Controls X _ X _

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Questions/Intelligence X _ X _

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Visual Elements X _ X _

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Use of Colour X _ X _

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Terminology X _ X _

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Error Messages X _ X _

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Tabbed Dialogs X _ X _

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Metaphors X _ X _

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Globalisation X _ X _

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