From the
Asilomar Institute for Information Architecture:
The structural design of shared information environments.
The art and science of organizing and labeling web sites, intranets, online communities
and software to support usability and findability.
An emerging community of practice focused on bringing principles of design and architecture
to the digital landscape.
From
"Information Architecture for the World Wide Web"
(2nd Edition):
The combination of organization, labeling, and navigation schemes within an information
system.
The structural design of an information space to facilitate task completion and
intuitive access to content.
The art and science of structuring and classifying web sites and intranets to help
people find and manage information.
For more definitions, see Defining the Damn Thing on
Elegant Hack and the
IAwiki.