Standardization of growth.

In considering the development of growth standards, four general questions need to be addressed. First, it is necessary to know why the standards are being prepared and in particular what questions will be asked of them. Second, the need for regular revision of these standards must be considered, together with the choice of interval between such revisions. Third, the relative value of national (as opposed to international or reference) standards must be established, and fourth, the requirements for the development of such standards should be taken into account.