ABSTRACT
The questionnaire of a poll must be filled in by all people selected in the sample. This can be done in various ways. These ways are called modes of data collection. This chapter describes the main modes of data collection. The researcher has to take a decision in the setup phase of a poll about which mode of data collection to use. Two important aspects will probably determine this choice: quality and costs. All data collection activities together are often called the fieldwork. In principle, this term refers to interviewers going into the field for a face-to-face poll. The four main modes of data collection are mail polls, face-to-face polls, telephone polls, and online polls. It summarizes the most important differences between the modes. The chapter also summarizes a number of advantages and disadvantages of the four main modes of data collection.
