I based the theory on information architecture system by Rosenfeld and Morville as they have outlined the basic principles about information architecture quiet good.
I chose to look use used Contextual Inquiry as a method to understand what problem the users was experience. The idea about Contextual Inquiry is that the interviewer trainee and the users has to teach the interviewer how to use the application. By using Contextual Inquiry, the structure of the work became implicit as the user told about what they were doing and it was easier for the user to pause and make a reflection of the action. Also the users would not be able to remember why and how they were acting on the rejsekort ATM after they did it, so it was important that I could ask them in the middle of doing it.