RVM Data Reliability

The RVM uses a combination of non-random and random sampling: non-random sampling in the selection of survey sites employed, and random sampling in the selection of respondents at those survey sites.

The use of non-random sampling means that not every visitor to a region has an equal chance of being selected: for example, visitors who do not visit the RVM survey sites have no chance for participation. As a result, it is not possible to accurately calculate sampling error in relation to the RVM data. However, it is possible only to say that the margin of error associated with the RVM data would not be lower than a margin of error for a similarly sized random survey (in this case +/- 2.3%) but it is impossible to know the upper limit of this margin of error.