Upload
fathi
View
22
Download
0
Embed Size (px)
DESCRIPTION
USABILITY. Based on a lecture by Raino Vastamäki, Research Director Adage Oy in Kiljava on May 2003. Definition. ISO 9241-11 - PowerPoint PPT Presentation
Citation preview
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 1
USABILITY
Based on a lecture by
Raino Vastamäki, Research DirectorAdage Oy
in Kiljava on May 2003
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 2
Definition
ISO 9241-11
• UsabilityThe 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 1.11.2003 / PV page 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 1.11.2003 / PV page 4
N Z O M NM Z N Z
N O O O ZM N Z M
Z N O N Z
N Z O M NM Z N Z
N O O O ZM N Z M
Z N O N Z
N Z K M NM Z N Z
N K K K ZM N Z M
Z N K N Z
N Z K M NM Z N Z
N K K K ZM N Z M
Z N K N Z
N Z K M NM Z N Z
N K K K ZM N Z M
Z N K N Z
N Z K M NM Z N Z
N K K K ZM N Z M
Z N K N Z
N Z KK M NM Z N Z
N K K KK KK ZM N Z M
Z N KK N Z
N Z KK M NM Z N Z
N K K KK KK ZM N Z M
Z N KK N Z
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 5
Why the users are so helpless?
1. Most of the human behavior is automated and unconscious• Examples of websites
www.afl-cio.org www.lo.se
2. Perception is fragmented and constructed
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 6
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 7
Designer’s model
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 8
Perceptual experience
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 9
Projection on primary visual cortex
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 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 www.sonera.com
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 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
• www.yle.fi
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
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 12
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 13
Dialog on - Usability Düsseldorf 1.11.2003 / PV page 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 1.11.2003 / PV page 15
Defining usersTask analysisContext analysisDefinition of usability requirements
Defining usersTask analysisContext analysisDefinition of usability requirements
PrototypesPrototypes
Navigation mapsNavigation 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-Usability tests
-Interviews-Questionnaires-Observation-Log information
-Interviews-Questionnaires-Observation-Log information
Product in use
Product in use
Defining requirementsDefining requirements
Preliminary designPreliminary design
Iterative planning
Iterative planning
Designing thegeneral structure etc.
Designing thegeneral structure etc.
Designing detailsDesigning details
TestingTesting
LaunchLaunch
RealizationRealization
ProductProduct
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 1.11.2003 / PV page 16
The usability heuristicsJacob 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
• www.useit.com/papers/heuristic/