Aug 26 - Definition of Usability

Usefulness is defined as the ability to achieve a goal by using the system. Usefulness can be divided into utility and usability. Utility refers to the functionality of a system, and usability to the ability to make use of that functionality (Nielsen 1995).

The usability of a system is determined by the usability of both the underlying system engineand the contents and structure of the information base. Usability has been associated with fiveattributes: ease of learning, efficiency, easy to remember, consistency (few errors) and pleasantness of use (Nielsen 1995).

A critical approach to an adaptive user interface design.Teija Vainio. Hypermedia Laboratory, University of Tampere, 33014 University of Tampere, Finland. E-mail: teija.vainio@uta.fi
Mikko Ahonen. Hypermedia Laboratory, University of Tampere, 33014 University of Tampere, Finland. E-mail: mikko.ahonen@uta.fi
Learning With Mobile Devices: Reserch and Development. a book of papers, edited by Jill Attewell and Carol Savill-Smith. Learning and Skills Development Agency, Regent Arcade House19–25 Argyll Street, London W1F 7LS. pg 189-192

Nielsen J (1995). Multimedia and hypertext. the internet and beyond. Boston: AP Professional, 280–281.