Performance of smartphone users with half-pie and linear menus

Abstract

ABSTRACTIt will not be easy for smartphone users to get accustomed to one-hand operation using smartphones with larger screens. Coupled with the massive data on the handset screen, the menu design has become extremely important. This study is to apply the pie menu into the smartphones which is used in previous PC user interface. Specifically, how efficient are the users when using pie menu on 5″ handsets? The experiment is divided into two phases. In Phase 1, behavioural analysis, 36 participants used their right hand to operate the Left-Side-Linear Menu (LSLM), Right-Side-Linear Menu (RSLM), and Half-Pie Menu (HPM) while walking. After the experiment we asked them to fill in the NASA-TLX (NASA Task Load Index Standard Workload Test). In Phase 2, eight participants with different thumb lengths and diverse operating experience were invited to operate three menu techniques while standing. Results showed that participants with shorter thumbs are more efficient in operating the three menu techniques than participants with longer thumbs. The reason for this difference is related to how the users grip their phones. In addition, LSLM has the highest error rate and RSLM has the lowest among the three types. The efficiency of HPM depends on continuous learning for five minutes and the result closely matches RSLM. However, there was no significant difference between the HPM and the LSLM in walking speed. In addition, 137 participants took the improved version of the test and made ‘Good’ comments in the System Usability Scale.