Field Evaluation of Personal Digital Assistant Enabled by Global Positioning System Impact on Quality of Activity and Diary Data

A custom tool, PARROTS [Personal Digital Assistant (PDA) system for Activity Registration and Recording of Travel Scheduling] was developed to collect both activity data and global positioning system (GPS) data. This tool is currently deployed in a survey carried out on 2,500 households in Flanders (Belgium). The GPS-enabled PDA data collection tool features default answers, predefined drop-down lists, and many other graphical design elements. Two types of data were collected using PARROTS: activity and travel diaries input by the respondents and location data logged by a GPS receiver. To judge the effect of the PARROTS tool on the quality of activity and travel diaries, a paper-and-pencil diary was designed and deployed as well, and various analyses were performed on both the paper-and-pencil and PDA data. For the collected GPS data, the data quality was investigated in terms of availability of location information in the logs. In addition to investigating data quality, the impact of using PDA technology on user response rates was examined and compared with response rates for the paper-and-pencil format. The PARROTS tool provided high-quality activity and travel diary data, and it enabled the collection of scheduling and rescheduling information that would be too burdensome to collect using paper-and-pencil surveys. Moreover, PARROTS was able to collect GPS-based location information, and it made the data readily available in electronic form, while keeping the burden for the respondents at an acceptable level.