The use of personal digital assistants for data entry at the point of collection in a large household survey in southern Tanzania

 This study used Personal Digital Assistants (PDAs) for data entry at the point of collection, to save time and enhance the quality of data in a survey of over 21,000 scattered rural households in southern Tanzania. Pendragon Forms 4.0 software was used to develop a modular questionnaire designed to record information on household residents, birth histories, child health, and health-seeking behaviour. The questionnaire was loaded onto Palm m130 PDAs with 8 Mb RAM. One hundred and twenty interviewers, the vast majority with no more than four years of secondary education and very few with any prior computer experience, were trained to interview using the PDAs. Thirteen survey teams, each with a supervisor, laptop, and four-wheel drive vehicle, were supported by two backup vehicles during the 2 months of field activities.

PDAs and laptop computers were charged using solar and in-car chargers. Logical checks were performed and skip patterns taken care of at the time of data entry. Data records could not be edited after leaving each household, to ensure the integrity of the data from each interview. Data were downloaded to the laptop computers, and daily summary reports were produced to evaluate the completeness of data collection. Data were backed up at the end of every module, onto storage cards in the PDA, and at the end of every day, to laptop computers and to a compact disc. A small group of interviewees from the community, as well as supervisors and interviewers, were asked about their attitudes to the use of PDAs.

Following two weeks of training and piloting, data were collected from 21,600 households (83,346 individuals) in July–August 2004. No PDA-related problems or data losses were encountered. After fieldwork ended, the full dataset was available on a CD within 24 hours and the results of initial analyses were presented to district authorities within 48 hours. Data completeness was over 99 per cent. The PDAs were well accepted by both interviewees and interviewers. Their use eliminated the usual time-consuming and error-prone process of data entry and validation. PDAs are a promising tool for field research in Africa.