In general, market research is about gathering information from the consumer on a particular product or company. It is done through primary and secondary research, where primary research is the act of gathering the information straight from the consumer, and secondary is gathering information off another media which has gathered information primarily. In terms of a restaurant, it would be ideal to mainly perform primary research, as you would to get a direct answer and observe facial reactions, be more accurate.

For a restaurant I would use a non - probability sampling as the researcher is choosing and separating different groups of people according to age, sex, etc, and then performing research within each group separately. This results in the fact that it is not possible state a sampling error based on statistical theory. The technique I would use to sample the population would be quota sample. A quota sample includes people or items that are chosen according to predetermined characteristics. It is a method which involves dividing the population into subsets with quotas that reflect the identity of the subset (e.g., age, sex, nationality, income). These are made on a non-random basis by the interviewer.

In this case, assume that we would want to research whether the community in Jeddah prefers casual restaurants or fast foods. We would set up a quota sample of a certain number of people of different age groups and specify that none of them are restaurant owners. Then research is conducted within these subgroups, asking questions such as, why they prefer their choice, whether they can afford it, what they like to eat and so on.

Now because we know fast food restaurants are aimed towards young children and teenagers, quota sampling would have to be used as the population is divided into subgroups of age, sex, nationality, etc. So now the interviewer knows who he wants to interview - children and teenagers - and he would know that the questions he shall ask have to be simple, possibly said in a way of showing excitement for smaller children to answering correctly.

Finally, in any research, geographical differences always have an effect on any plan. For example, different areas will be used to a certain food, or taste, and so answers will obviously vary from area to area.