Human Computer Interaction

Ergonomic Evaluation of the GPS Message Display Terminal Used in Singapore Taxis

Paper presented in the 8th South East Asia Ergonomics Society Conference, May 2005, Bali, Indonesia.

Ketut Sulistyawati, Rosemary Ruiz Seva and Kee Yong Lim
Centre for Human Factors and Ergonomics
School of Mechanical & Aerospace Engineering
Nanyang Technological University, Singapore 639798

Abstract
A Global Positioning System (GPS) for taxi booking is currently being used in Singapore to enhance the effectiveness of taxi booking and dispatching. The system comprises a central coordinating headquarters and mobile reception terminals in taxis called Mobile Display Terminals (MDT’s). These terminals are placed next to the taxi dashboard to the left of the drivers and are used to display messages sent from the headquarters to the driver. As both the MDT and driving tasks are visually demanding, appropriate design of the device is vital to ensure safety. For this reason, the design of the MDT has been evaluated through observations and interviews with taxi drivers. Three different MDT’s in use in Singapore have been assessed in terms of their display design and usability. In addition, the advantages and disadvantages of a GPS MDT are compared against the preceding radio based system. The results of the analysis suggest that the MDT is effective in conveying information to the driver. More recent designs that use color, icons, and digitized voice messages are found to be more user-friendly. However, there are some ergonomic issues that remain unaddressed by these designs, such as overlapping buttons, obscure icons, menu arrangement, and screen luminance. Specific recommendations to improve the existing systems are presented in this paper.

Electronic map display design and its effects on team performance

Paper presented in the National Seminar on Human Aspects in Computer-based System, September 2005, Bandung, Indonesia.

Ketut Sulistyawati, Kee Yong Lim &Yoon Ping Chui
Centre for Human Factors and Ergonomics
School of Mechanical and Aerospace Engineering
Nanyang Technological University
50 Nanyang Avenue Singapore 639798

Abstract
In helicopter cockpits, information about the terrain and enemy forces can be presented in the form of paper and/or electronic maps. Unlike paper maps, electronic maps equip pilots with real-time information on the operation context. With the prevalence of electronic map use, the effectiveness of the display design in conveying information to the pilots needs to be evaluated. In particular, it is essential to assess how the design influences team performance. An experiment is set up to simulate a helicopter cockpit environment. Six teams consisting of a pilot and copilot are recruited to perform navigation and enemy engagement tasks using an electronic map. The effect of the information presentation of the maps on team behavior and performance are analyzed. Team performance is evaluated for two tasks: navigation and enemy engagement. Errors committed by team members due to the display design are identified. A discussion of how the display design affects team performance is presented in this paper. Recommendations to improve the display design of an electronic map are also proposed.