In 2005 the Office for National Statistics (ONS) in collaboration with Dan Vickers and Phil Rees of the University of Leeds, released a free small scale social area classification of the UK based on 2001 UK small area census data. Similar classifications had been developed for earlier censuses, notably by Stan Openshaw and colleagues at Newcastle and Leeds Universities, but access to these generally was restricted to the academic communities. The 2005 Output Area Classification (OAC) and the 2013 release of Acorn in the UK is a move to 'open geodemographics' and reflects a concern that applications of commercial geodemographics in policy and social research can otherwise be 'black box': it is not always clear exactly what variables were used to classify small areas and to define their neighbourhood type, how those variables were weighted, or how similar (or otherwise) each of the neighbourhoods within a class type actually are. Open geodemographics provides such information (because it is not constrained by commercial interests) and is an important development for applied social research that also seeks to understand and to explain the roots causes or processes that generate aggregate spatial patterns of social behaviour and attitudes. The Output Area Classification is now supported by a user group here. CACI have also released detailed documentation on how their classification utilizes Open Data here. Geodemographic profiles have widened their application in the UK, with many life insurance companies and pension funds using them to assess longevity for pricing and reserving. In Australia, general purpose geodemographic systems summarises a broad range of profiling data, largely derived from the Australian Census to create a thumbnail sketch of the type of people living in a particular small area. These small areas are either CCD (Census Collection District) or a sub-CD area, like a Meshblock. The types of characteristics mainly taken into account in geodemographic system construction are:  In 1987, geodemographic systems were first introduced as social analysis tools with CCN's (later Experian) introduction of the MOSAIC system. In 1990, RDA Research built their first system, geoSmart. Geodemographics has drawn critical attention. Some focus on the possible discriminatory and intrusive effects of geodemographic practices. Others wonder whether members of geodemographic groups really are sufficiently alike to be analysed together. The generally unknown variance within geodemographic groupings makes it difficult to assess the significance of trends found in data. This may not matter for commercial and service planning applications but is of some concern for public sector and social research.