Empirical Evaluation of a Popular Cellular Phone's Menu System: Theory Meets Practice
http://www.usabilityprofessionals.org/upa_publications/jus/2006_february/cellular_empirical_evaluation.pdf
  peer-reviewed

Huang, Sheng-Cheng, I-Fan Chou and Randolph G. Bias
Journal of Usability Studies
2006

Abstract:

A usability assessment entailing a paper prototype was conducted to examine menu selection theories on a small screen device by determining the effectiveness, efficiency, and user satisfaction of a popular cellular phone's menu system. Outcomes of this study suggest that users prefer a less extensive menu structure on a small screen device. The investigation also covered factors of category classification and item labeling influencing user performance in menu selection. Research findings suggest that proper modifications in these areas could significantly enhance the system's usability and demonstrate the validity of paper-prototyping which is capable of detecting significant differences in usability measures among various model designs.