Data collecting stage is about gathering problem specific data. This stage has two important decision aspects: sample design and data collection forms. Sample design provides a description of the population to be studied and how it will be defined. For example, if a pet food producer wants to investigate buying habits of its customers, the ones who do not have a pet are needed to be eliminated from the sampling frame. The researcher specifies the population, states the desired sample size based on research budget. If a non-random sample is to be used, the justification and type of sampling strategy to be employed, such as convenience sample, are stated. Data collection forms to be used are formed at this stage. This stage involves either a questionnaire or an interview schedule.