Marketing demand means the aggregative demand of all the consumers in the market for a commodity or service at a particular price. Market demand is always defined with reference to a price and a time period.

The two methods of marketing research are as follows:

1. Observation Method: Observation refers to the process of recognising and noting facts or events. Under this method, the behaviour of consumers is watched through personal observation or mechanical devices. It avoids the pitfalls of questioning such as interference in the consumer’s activity, bias of the interviewer and distortion due to the consciousness of being questioned. 

2. Experimentation method: Under this method, a control market is established in which all forces except those being tested are kept under check. It seeks to test a theory or to find consumer’s reactions. The method involves a large expenditure of time and money. It requires skilled investigators. Moreover, it is difficult to select test markets and to control the variables.