Although the term was not designed to relate, originally, to the field of structure design, there are some parallels that we can draw to help illustrate what we are doing.
We want to take the information of a company, the who-what-where-when-how, and define it, categorize it and give it an intelligent place to exist so that users can relate to it and understand it.
An architect designs space to contain conceptual usage of that space. IAs define access to information spaces.
An architect also designs the way you access these spaces as do Information Architects in conjunction with Interaction Designer, begin to lay out a structured way of accessing the information that has be laid out and categorized, giving the user a way to navigate these “info-spaces”.