How do you decide the right variables to control on? The sample supplier needs to understand the objectives of the research as well as the analytic plan in order to make solid recommendations. Without this understanding it is difficult to build an appropriate sample.
A running theme through the 82 pages of the most recent Greenbook Research Industry Trends Report (GRIT) is that the quality of survey sample has eroded to the point of crisis for market research.
The New York Times and CBS News recently announced the use of online panels as part of their election coverage polling. This reignited the online/phone quantitative research debate.