- How the user interacts with the product.
- What information the product presents to the user.
- What information the user supplies to the product.
User interaction designers and user interface designers are information architects.
FYI, the Wikipedia entry on information architecture notes:
An alternate definition of information architecture exists within the context of information system design, in which information architecture refers to data modeling and the analysis and design of the information in the system, concentrating on entities and their interdependencies.