Top Market Strategy

2.2 Sampling

The population for a customer survey is all customers who qualify for the survey, whereas a sample is a group of customers selected from the population. Probability sampling methods assume that the entire sample responds—an unrealistic requirement—so most survey researchers prefer nonprobability sampling in general and quota sampling in particular (Table 4). They usually perceive quota sampling to be less biased and more cost effective than other sampling methods.

When a quota sample is sizeable and proportionally represents all potential respondents, you can expect that the responses of these respondents generalize to the population. ...