Field services are limited-service suppliers who specialize in data collection. Limited service suppliers specialize in one or more specific task associated with the research project. Limited services suppliers can create cost saving in data collection. A supplier can conduct telephone or face-to-face interviews at a lower cost than can the firm’s marketing research department, because they can generate enaugh business to keep they interviewers busy full-time (Crask Melvin, et al. 1995)
Sigma Research has experienced interviewers in 15 big cities in Indonesia. From the determination of the number of samples, criteria of respondents, and quality control is considered and has become the company standard.