Comparing User Performance on an iPad to a 17-inch BackPad

What will a truly large iPad be like? Will it have a touchscreen atthe front, or will some other changes be forced by the sheer sizeof the device? We mocked up a working device using a 17-inchMacbook laptop screen. The device size was too large for us tocomfortably hold with one hand while using the other hand fortouch input, so we placed the touch pad at the back. Hence, wecall our device a BackPad. In the first experiment, we compareduser performance with our 17-inch BackPad and a normal iPadin game and typing tasks. The results on the game completiontime and score were similar, and users liked our large screen,while time but not spelling errors were different in the BackPadversus the iPad. For the second experiment, we compared thefront touchscreen versus the back trackpad user performance onsame sized devices. Similar results to the first experiment werefound on game completing time and score.