I am very interested in Human Computer Interaction (HCI) classess I am taking now. So this time about mental models that we were looking at.
The idea of the mental models seems very useful to me, as it is important to take into account what is going on in people’s heads in order to make a successful user interface design (and of course other kind of design). With the successful design I mean one that user can learn easily and naturaly and use it effectively.
OpenID interface proposal
As the task for discussions in HCI class we needed to prepare proposals for a successful OpenID interface. We had to test the design on one user at least. In my case I used the Skype screen-sharing feature to watch and listen how my girlfriend is using various OpenID log in designs, such as Facebook, Twitter (at RWW to comment an article).
I immediately noticed a problem that different services puts different contexts on log in feature. In other words, users might think that by logging in by, for instance, Twitter account, it not only allows to post a comment in RWW, but also affects her Twitter accout (will a note appear in my Twitter? will I be required to follow someone?).
So I tried to develop common interface for all services (Facebook, Google, Twitter etc.), meaning that there won’t be differently designed pop-up windows, only similar username/password/url text boxes. However, I guess this violates the idea of OpenID, that you are redirected to the authentic website (e.g. Facebook) to confirm your data in order to log into website (such as RWW). Otherwise, I personally would be hesitant to share my Facebook password with other website I don’t know.
So, my design was more like attempt to highlight a problem of different contexts in OpenID log in design.
Different understandings of OpenID
In the class we tried our designs on each other. I was surprised how diverse understandings (mental models) about OpenID were. And I was more surprised that each person defended their own mental model (belief?) quite convincingly, even if their mental model was incorrect. For instance, some people claimed that OpenID is a big database containing all password, while some people said that in their understanding it is decentralized collection of databases.

Mental models (http://middledigit.net/)
What is a mental model?
Before reading books, doing excercises and having discussions I had very blurred understanding of mental models. I knew that this is something that happens in people’s heads, but that’s all. How can that be used in design, and why? Does it change by the time? Do everyone have their own mental model and does it differ a lot? There were many questions I had no clue about (actually I didn’t have questions before that
).
From a book I understood that main concepts of mental models are information processing and external cognition.
Information processing
The mind is thought as information processor. Information comes into mind, goes through various processing stages (comparing, matching) and goes out in form of behaviour (including, no reaction at information). There is much interest in calculating how long does it take to perform a certain task.
Of course, there is limited amount of information that is possible to process. That creates bottlenecks in procession information.
Information overload is a common concept nowadays, so there is a need for structuring information, so I guess librarians and information designers (in physical world) together with information architects (in digital world) are doing a great job in making a complex clear.
As I am personally interested in information architecture and am following community for a longer time, I have noticed that there are some difficulties in defining this practice. However, I am glad that effort in explaining IA is being made and on right side there is a pretty neat explanation if IA. I guess something the same could be with information design practice.
External cognition
This concept refers to thought that people interact with or create information through using a variety of external representations including books, maps, diagrams, notes, images.
This is for reducing cognitive load:
- memory load,
- computing,
- and to reflect changes (crossing out what’s done, manipulating models).




