In marketing research what is the principle difference between Primary and Secondary data? Suggest two methods of data collection for each.

Primary data is considered data researched by current evaluations using surveys, experiments or similar strategies. Primary data is usually collected specifically for the targeted area, field, audience, product, etc. It is more reliable and of high information value but an expensive and time-consuming way of research.

In contrary, secondary data or "desk research" is historical data which can be collected by publications in news, magazines, the internet or other sources. Secondary data ist in fact more general and not as specific as the primary counterpart, yet more convenient and cheaper.

Depending on reliability, informative value, financial budget and timeframe the appropriate method should be considered.