Software testing between two applications (Desktop and Mobile)

Question

I'm developing a mobile application for WP7 based on an existing Silverlight desktop application. I want to perform a test comparison between both applications concerning the user interaction and experience. I known that exists several software testing methods. But none of them fit in what I really want to test, which is having the right metrics to perform the comparison. Right now I believe that Usability Testing is the closest from what I want that is:

• Compare the way of performing similar actions
• Compare the degree of similarity
• The adaptability capacity of using the mobile app against the desktop application

Sorry for the weird question :P And thank you in advance...

Answer 1

The tests you describe are all very subjective.
I don't see any approach other than testing manually.