For The Web
Information architecture is a practice that’s committed to improving the experience of human-computer interaction. It achieves this by engineering the structure of application user interfaces.
As humans interact with computing interfaces, we increasingly contribute to our own personal and networked web of information and information relationships. Over time we naturally become dependent on the information we’ve stored to recall previous knowledge or to influence and create new knowledge. However, as our personal and organizational repositories of information grow, it becomes more challenging to discover, interpret, manage, and use information in an efficient manner.
To ensure the future usability of application user interfaces, we must plan for environments of scale and complexity. If not, much of the information that we retain and the user interfaces that we design will become unusable.
Beyond the Web
Skilled IA practitioners can be employed to document abstract and ambiguous aspects of any environment into an understandable and actionable model. The subject domain does not have to be an application interface.
While the computer interface is the primary domain of interest for most, a future aspiration of many practitioners, including myself, is to extend the practice of information architecture beyond pure business interests.