Dialog on - Usability Düsseldorf / PVpage 1 USABILITY Based on a lecture by Raino Vastamäki, Research Director Adage Oy in Kiljava on May 2003

Dialog on - Usability Düsseldorf / PVpage 2 Definition ISO Usability The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.

Dialog on - Usability Düsseldorf / PVpage 3 Why the users are so helpless? 1.Most of the human behavior is automated and unconscious Example: We see first Image before text Movement Large before small Dark before light Color before black and white Saturated and warm colors Strange before familiar Unexpected things Strong contrasts...

Dialog on - Usability Düsseldorf / PVpage 4 N Z O M N M Z N Z N O O O Z M N Z M Z N O N Z N Z K M N M Z N Z N K K K Z M N Z M Z N K N Z N Z K M N M Z N Z N K K K Z M N Z M Z N K N Z K N Z K M N M Z N Z K K K N K K K Z M N Z M K Z N K N Z

Dialog on - Usability Düsseldorf / PVpage 5 Why the users are so helpless? 1.Most of the human behavior is automated and unconscious Examples of websites   Perception is fragmented and constructed

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Dialog on - Usability Düsseldorf / PVpage 7 Designer’s model

Dialog on - Usability Düsseldorf / PVpage 8 Perceptual experience

Dialog on - Usability Düsseldorf / PVpage 9 Projection on primary visual cortex

Dialog on - Usability Düsseldorf / PVpage 10 Why the users are so helpless? 3.The users see only the interface, they don’t see the system as a whole 4. What is obvious for designers is strange for the user 5. The users are unfamiliar with the organization and the used terminology Example of a website 7www.sonera.comwww.sonera.com

Dialog on - Usability Düsseldorf / PVpage 11 Why the users are so helpless? 6.Different user interfaces operate in different ways - sometimes even the same interfaces are not consistent Example of a website 7. The fonts are too small Minimum size 11–12 pt Use high contrasts Use lower case (abc) not upper case letters (ABC) Enable the user to change text size Don’t use red and green of same saturation together

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Dialog on - Usability Düsseldorf / PVpage 14 Designing usability ”The user interface is not the paint put on at the end of the project, but the steel frame on which to hang the details” Ben Shneiderman, Designing the User Interface 1987

Dialog on - Usability Düsseldorf / PVpage 15 Defining users Task analysis Context analysis Definition of usability requirements Defining users Task analysis Context analysis Definition of usability requirements Prototypes Navigation maps -Iterations -Usability tests -Heuristic evaluations -Cognitive walkthroughs -Guidelines, standards, principles -Style guides -Design rationale -Iterations -Usability tests -Heuristic evaluations -Cognitive walkthroughs -Guidelines, standards, principles -Style guides -Design rationale -Usability tests -Interviews -Questionnaires -Observation -Log information -Interviews -Questionnaires -Observation -Log information Product in use Defining requirements Preliminary design Iterative planning Iterative planning Designing the general structure etc. Designing the general structure etc. Designing details Testing Launch Realization Product Website development -Discussions -Meetings -Interviews -Questionnaires -Log information -Usability evaluations of existing products -Discussions -Meetings -Interviews -Questionnaires -Log information -Usability evaluations of existing products

Dialog on - Usability Düsseldorf / PVpage 16 The usability heuristics Jacob Nielsen 1994 Visibility of system status Match between system and the real world User control and freedom Consistency and standards Error prevention Recognition rather than recall Flexibility and efficiency of use Aesthetic and minimalist design Help users recognize, diagnose, and recover from errors Help and documentation