The Think Aloud user testing worked quite well, as we could figure out some aspects of our design that should get changed. We run two tests with one male and one female user, who both were familiar with mobile phones and internet. The experiments took place one at Marius's place and one at Stefan's. The testusers sat in front of the computer - music and other noises (ICQ messages etc.) were turned off in order to reduce disturbances. The following instructions were given to the users:

• Someone nearby has the Norman book. Find and buy it!
• Look and verify your offers!
• You just got a new message! Read it!

After the users had finished their tasks they were interviewed. We wanted to find out where they thought we could apply some improvements.

Here are our results regarding our necesarry design changes:

• The 'Browse' icon should look more like a human hand.
• Lacking some english knowledge one test-user did not understand the meaning of the 'Browse' icon, so she went through every menu until she found the desired function. We decided to add a link (leading to the browse section) in 'My Search' as the functions are related to one another.
• user testing revealed some implementation inconsistencies regarding consequences after double-clicking an optional icon: while leading to the "view details" screen after item-double-clicking starting from "Browse-"category in the categories "MyOffers" resp. "MySearch" nothing similar happened.
• Checking the inbox messages status, the little yellow star (indicating an incoming message) was overseen by one user. We decided to provide additional highlighting of the message subject starting form the expectation of more ease of use detecting new messages.