In Jessi James Garrett's book, Elements of User Experience there is this image that shows up that presents various facets of the User Centered Design process...
On the structure line, he separates Interaction Design from Information Architecture. What are specific characteristics that pertain to one and not the other?
Information Architecture - IA - in a literal way tells how the the information is architectectured or arranged or designed on any application. Ideally it shows the directions for a user to reach to a specific location containing the info user is looking for. And for that there are several things like - navigation, controls, signs, - which account for the correct IA, leading the user to a place with as much less hassle as possible. Peter Morville & Louis Rosenfeld have an excellent book callled ' Information Architecture for the World Wide Web' which extensively and clearly talks about IA.
Interaction Design - IxD - deals with user actions leading to certain reactions from the device or application they are working on to complete a specific task or achieve a certain goal. Alan Coopers book - About Face 3: The Essentials of Interaction Design talks about this.
Although these books are popular they are not the only one's written about IA and IxD. There are more several books about these.
So to differentiate them both:
IA looks into the layout, navigation and its types, wayfinding, search systems, labelling and so on..
IxD deals with (designing) how to aid user actions and subsequently triggered reactions while allowing the user to accomplish what they have set out for. Touch screens, voice activations, audio help and so on are the types of interactions.
Indeed, both are subjects (and their distinct characters) that can be discussed elaborately.
Elements of User Experience is a must read. JJG's book is one of the few books I kept from college, the rest I sold.
I always saw the difference as Where and How.
With Information Architecture (IA) you decide what the logical place is for certain pieces of information. Where will the visitor look for that piece of information.
Interaction Design is about how the visitor will get there. It should be easy and logical in the eyes of the visitor.
A simpler way to look at the difference between the two would be to view Information Architecture as the part of the structure relevant to the content of the interface, whereas Interaction Design is part of the structure relevant to the flow/transition of the interface. I would have actually swapped Information Design with Information Architecture on this diagram, and changed the term Information Design to Content Design.
UX Design, Interactive Design, Front-end Design, etc. are merely sub-sets (examples) of Information Architecture. IA is the science behind Collecting, Structuring, Presenting, and Comprehending information. Period. No where in that definition should you see website, application, software, etc.. If you do, then it's incorrect (wiki is wrong). Web pages and applications are merely two of the many tools used in presenting information.
I'm using Information Architecture right now to logically structure my information in a way that makes it easy for readers to follow and comprehend. I'm using this site as a tool to present my information. Now bear in mind that this may not be structured in the best way possible, which is why IA is a continuing science and not a standard.
NOTE: This Exchange (UX-User Experience) should have been named Information Architecture. UX falls under IA - IA does not fall under UX.
Information architecture will show you where content should live and how it is grouped with other content. Interaction design is the model for moving through that content.
Let's look at an example. If you have a shopping site, your information architecture might look like:
Shop
There are many ways to design the interaction for navigating this information architecture. Take a look at many of the shopping sites out there today. You might see a horizontal navigation with dropdowns, a vertical navigation with sections that expand and collapse. It's popular now to have a "megamenu", a single large "Shop" panel that opens up from the horizontal top navigation to display all of the product types.
An interaction design will often go beyond the information architecture to describe how login screens, empty data sets, shopping carts, or countless other details should be experienced. Sometimes the needs of a good interaction design will change the shape of the information architecture and vice versa.
