HCI Briefings

Information Architecture

The focus of web design is still too often on what the site does, and what it looks like, rather than on the organisation of the content. In these cases, whether or not a user will be able to get what they want from a site seems to have been left to little more than chance. Sites with an insufficiently planned structure confound users and prevent them from achieving their goals. For a website to succeed it is imperative that users are able to find what they are looking for, and this requires that the information on it is organised in a clear and logical structure.

Information Architecture (IA) is the business of analysing this information and developing the structures necessary to facilitate user tasks. Good IA is synonymous with good usability, because a well-designed structure makes it easy to define a navigation system, page layouts and templates. However, without efficient IA, good page-by-page usability is wasted for want of a solid foundation. The term ‘architecture’ is used here for a very good reason: information architects provide the blueprint for a site on which all other aspects are built.

Facilitating user tasks is more complicated than it may first appear, for a number of reasons. First and foremost, users and the computers that they are interacting with form complex systems, which are not easy to second-guess (nor should we try). Structuring information in a way that is meaningful to normal people (not just to you, your manager or a person doing your job in another company) is a difficult business. Secondly, users are not interested in comprehending the structural aspects of a site, merely in achieving goals, and if they can perform tasks without knowingly having to grapple with how information is organised on the site then so much the better. The IA has to be invisible to a large extent, while being logical and intuitive to users. This is why, although IA is an easy skill to pick up, it is an extremely difficult one to master. IA must take account of existing networks of knowledge within an organisation and externally, between users. It must also acknowledge the different types of behaviour that users will exhibit when seeking information – such as searching or browsing – and the different manner in which information must be organised to accommodate these.

Information architects not only define the hierarchical structure of a site, they also determine aspects such as navigation by dictating which items belong to global navigation systems (the links or options that appear on every page), which are local (the menu systems that apply to sub-sections of the site) and which contextual (links and controls which appear within a page). Structure and navigation systems are both arrived at by using taxonomies. A taxonomy is a classification system which groups information into categories where every item is mutually exclusive. Once organised into a taxonomy, information lends itself to logical menu structures and navigation systems.

The identification and classification of individual items of information also presents an opportunity to consider their meaning to the user. Jargon and/or industry-specific words are often not representative and do not differentiate between menu items sufficiently for most users. These terms can be identified during IA development and replaced with labels that accurately communicate their content to the user. The information architect can develop controlled vocabularies of meaningful terms for each concept, and accepted variants. This helps promote consistency throughout the site.

Once taxonomies, structures, navigation and labelling systems have been designed, the information architect can develop wireframes (low-detail paper designs) to illustrate to the designer how these concepts can be implemented. Design of the aesthetic aspects of the site can then proceed, building apon the IA and wireframes to produce final designs. Users should now be easily able to locate the information that they require. Sites with good information architectures allow users a greater degree of success in achieving this than sites whose information structures have been allowed to develop in an extemporary manner.

Further Reading

Rosenfeld, L. & Morville, P. (2002) Information Architecture for the World Wide Web, 2nd Edition, O’Reilly, Sebastopol, CA, USA.

Online tutorial at Webmonkey: Information Architecture
(accessed 5th June 2003)