Market research conducted as and when required for a specific problem that the organization is facing is called ad-hoc market research. It is one-off, and has the purpose of helping the firm to solve a particular issue it is currently facing.
Continuous market research is an alternative type of market research, which is done on a regular and on-going basis, rather than a one-off basis (ad-hoc market research).
Primary market research involves the gathering of new data and information, because these do not currently exist. Primary market research involves fieldwork so is often referred to as field research. The main methods of primary market research are: surveys, interviews, focus groups, and observations.
Secondary market research involves the collection of data and information that have already been collected by another source, i.e. the data or information already exist. Hence, fieldwork is not required as the researcher can do this from the comfort of their own office (which is why secondary market research is also known as desk research). The main sources of secondary market research are: market analyses, academic journals, government publications, and media articles.