9 months after I completed my thesis, and I only just found IanBruk's request. Sorry!
Not having a copy of my thesis around atm, I'll do my best from memory.
My thesis was an empirical study on user preference for design features in the shopping cart, display of products (& navigation involved in purchasing them), and touched briefly on the checkout process. User preference is part of "usability" - with the other major component being user performance, which I didn't touch on.
I performed a series of indepth, interview style experiments with a range of subjects, asking them to compare various approaches to the items I mentioned above. For example, I looked at what information users want to be presented with when viewing a full version of the shopping cart. I also looked at what kind of confirmation users wanted when they attempted to purchase a product - when they hit "buy product" did they want a pop-up window with confirmation, did they want to be taken to a shopping cart with the item shown, did they want to remain on the same product page with the item updated in a persistent shopping cart, etc etc.
The result that I remember most clearly is that the majority of users like the concept of a persistent shopping cart. The only concern expressed was that a persistent shopping cart may take up valuable white space. An solution to this problem is to have a self tailored, or expandable/shrinkable persistent shopping cart.
Also, a large number of subjects indicated that they might like a "shopping cart link" to open a shopping cart in a new browser window, as long as that browser window remained up to date with any further purchases they made. In that way, it would be similar to a persistent shopping cart, but just existing in a separate window, and not taking up above the fold white space.
Thanks for your enquries. Since I started (and finished) my thesis, a wealth on information has become available regarding usability and e-commerce interface design. A google search these days will return many more results than what it did while I was a struggling research student. Readings that I found particularly useful included worked by Jared Spool and Jakob Neilsen. Useful sites included Forrester & ZDNet. Dack's page that RandyW suggested was also helpful (though the relevant page has been taken down now).
Back to work.
