I am now conducting research regarding mobile user experience. The experiments we are running consists of at least 4 dimensions.
Tasks need to be clearly defined with a broad range of simple to complex depending on the application.
Device used and OS will be a big factor in determining user experience. Especially for mobile devices where screen size is limited, the functionality of the software and how it integrates and utilizes the display is critical. Some buttons or icons on some display sizes may be unrecognizable on others.
This of course will impact user experience. We have to compare apples to apples in doing our benchmarking. Apps will be compared to themselves across versions, and also apps of similar kind where we can define exactly the same task can be compared. For example, buying a book on amazon versus barnes and noble.
Not all users have the same preferences. Older folks perhaps need bigger buttons or bigger font sizes, or perhaps simplicity is more important than function. Simplicity rules in all cases generally.
If you have any input or ideas on how we can improve our research or would like to participate, please give me a buzz. email@example.com
We have some usability and user experience whitepapers on our site as well if you just want to learn more. www.xbosoft.com