ABSTRACT
The first step in data collection is identifying the study population and drawing a sample of participants from it using either probability or nonprobability sampling. Statistical power analyses determine the appropriate sample size. Important considerations in data collection include pilot testing, choosing the research setting, creating clear instructions, debugging the procedures, running participants, and conducting the post-experimental interview. This chapter explains how to conduct Internet research, which is economical and provides access to hard-to-find research participants; however, an Internet sample can be biased, only certain types of studies can be conducted online, and the researchers lose some control over the data collection environment. Internet recruitment procedures are discussed, including the use of crowdsourcing. Ethical issues unique to Internet research are reviewed, including voluntary participation, informed consent, participant welfare, participant privacy, and debriefing. Archival data includes statistical archives, survey archives, or written and electronic records that can be used to study populations not usually available; this methodology poses few ethical problems. Difficulties include limited access to data sources, potential validity issues, and the inability to rule out alternative explanations for findings. The chapter concludes by discussing the ecological fallacy—inferring individual level processes from group level data.
