PROGRESS WITH DATA CENTRES Available to Purchase

Critical reference data may be defined as the critically evaluated measurements of basic properties of definable systems. Such data are selected after rejection of inaccurate or ill‐defined measurements or measurements which do not relate to definable properties and materials. The earlier collection and compilation of reference data was confined to areas where there were groups of scientists willing to undertake the compilation and where there was a clear interest in their use. Following the recognition that the task of critical data compilation, long left to individuals or groups, needed proper examination, co‐ordination and financing, some centres, a notable example being the National Bureau of Standards, United States, have undertaken a broad and systematic attack on the problem to identify and fill the gaps and to ensure a uniformly good quality of output. In June 1963 a National Standard Reference Data System was established within the administration of the National Bureau of Standards, the actual responsibility within the NBS being assigned to the Office of Standard Reference Data. The extent of the activities of the NSRDS at the present time is surveyed in NBS Technical Note 448 which lists in detail the data activities falling within the national data system.