Pollution control is a good subject for a data verification theory, one whose relevance is, sadly, destined to grow. In this chapter we consider the monitoring of compliance with regulatory limits on the emission of pollutants from a point source. Our objective is to introduce the concept of statistical testing and to derive a theory for the optimization of variables sampling procedures.

The term variables, in connection with verification by random sampling, was discussed briefly in the introduction to the second chapter. Here is a regulator's definition (US Gov. (1957)):

The reader might now be forgiven for wishing to skip the present chapter altogether, so we'll return (hastily) to our earlier definition: The variables sampling procedure is one which explicitly takes into account measurement errors. The differences between the inspectee's reported data and the inspector's findings are evaluated quantitatively; see for instance Encycl. (1982). Therefore there exists a chance of mistakenly concluding illegal behavior, that is, false alarms are possible.