In the field evaluation of the impact of a GPS-enabled personal digital assistant on activity-travel diary data quality

Abstract

Abstract. A custom tool, PARROTS (PDA system for Activity Registration and Recording of Travel Scheduling) was developed to collect both activity data and GPS data. This tool is currently deployed in a survey that is carried out on 2,500 households in Flanders (Belgium). This paper discusses the findings on the effects of a GPS-enabled PDA data collection tool featuring default answers, pre-defined drop-down lists and many other graphical design elements on data quality. Two types of data are collected using PARROTS: activity-travel diaries inputted by the respondents and location data logged by a GPS receiver. To judge the effect of the PARROTS tool on the quality of activity-travel diaries, a paper-and-pencil diary was designed and deployed as well and various analyses were performed on both the paperandpencil 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 is examined and compared to response rates for the paper-and-pencil format. Based on the above analyses, the performance of PARROTS as an activity-based survey data collection tool is assessed.