Methodology to be used in this research is presented in this chapter which the author undertakes it in the investigation of factors with the decision-making process affected on the frozen food purchasing in Bangkok, Thailand. This chapter is structured into the following items: (1) research philosophy; (2) research approach; (3) methodological choice; (4) research strategy; (5) data collection method; (6) sampling method; (7) pilot testing; (8) Reliability; (9) data quality; (10) data analysis, and at the end the chapter conclusion.