I'd be interested in the methodology, but I'm not willing to pay $30 for the full paper. I find that a sample size of 5 people to be really too small to draw a good enough conclusion. Also, I think the same person should not be performing tasks on phones of different sizes. The person who uses a phone of a particular size first, may get used to that size and may skew the results of other sized phones. I think you need at least 30 people for each phone of the different sizes before you can really draw a reasonable conclusion on usability.
The study measures both speed and accuracy. The researchers found that a 4" screen generated the fewest errors while a 3" screen had the fastest times. I would be interested to know exactly what operations the subjects performed on these devices and the nature of the errors.
The study measures both speed and accuracy. The researchers found that a 4" screen generated the fewest errors while a 3" screen had the fastest times. I would be interested to know exactly what operations the subjects performed on these devices and the nature of the errors.