Usability: An Important TC Topic
Usability is an important design consideration in software and website design. A designer concerned about usability is concerned about the ability of users to use the software with minimal problems. A more precise explanation is given in the ISO standards, which breaks usability into its components elements: 

The ISO 9241 standard describes ergonomic requirements for office work with visual display terminals. This standard defines how to specify and measure the usability of products, and defines the factors which have an effect on usability.  In order to specify or measure usability it is necessary to identify the goals and to decompose effectiveness, efficiency and satisfaction and the components of the context of use into sub components with measurable and verifiable attributes. 

(a) Effectiveness is the accuracy and completeness which specified users can achieve specified goals in particular environments. 
(b) Efficiency refers to the resources expended in relation to the accuracy and completeness of goals achieved. 
(c) Satisfaction refers to the comfort and acceptability of the work system to its users and other people affected by its use.

Steps in designing for useable systems
- Know thy user 
- Know the structure of the information/task the user needs to do 
- Design with usability in mind 
- Conduct usability tests early and often 

Useful Web Links
- Usability Professionals Association 
- Useit.com - Jacob Nielson's Usability Website 
- Usability Methods Toolbox 
- Web Usability Issues 
- Article on Universal Usability 


Important People
Names 		Why Famous 
Nielson 		Discount Usability Concept 
Norman 		1988 User Centered Systems Design  
Vanderheiden 		Promoter of Universal Usability