Researchers are increasingly considering the adoption of electronic data-collection methods--which entail the use of the Web, e-mail, and desktop and handheld computers--for surveys, diaries, research instruments, and focus groups. Based on prior research findings on electronic data collection, the authors delineate the key factors, which incorporate population, data, and resource characteristics, that guide researchers in selecting the data-collection method most appropriate for their research question. Population factors to consider in data-collection decisions are age, gender, socio-economic status, and access to technology. Key data factors influencing the selection of collection method include sensitivity of the topic, time sensitivity, longitudinal data, and contextual data. Data-collection decisions are also based on financial, time, and technological resources. Technology and demographics will continue to change and affect data-collection methods and possibilities. By examining these key factors, however, researchers will be able to reach data-collection decisions that are appropriate for each project.