Once statisticians and relevant groups of users jointly have identified the required statistics, statisticians should turn to existing sources in order to assess the extent that available data responds to users' needs. Some of the data needed are routinely collected by the national statistical system; some data are available but do not reflect gender differentials or present biases; and some data are not collected through regular data collection programmes.

Existing sources should then carefully be scrutinized in order to assess to what extent concepts and methods used in the data collection adequately reflect gender issues. Also, data gaps in existing data collection programmes have to be identified.

A large part of the efforts for the improvement of gender statistics should concentrate on these crucial steps. International guidelines for data collection focus on ways to improve the design and implementation of surveys and for extending the coverage to gender issues overlooked by the conventional data collection of countries.

The review of available statistics reveals data gaps, both in terms of issues not addressed by surveys and in terms of issues that are not adequately reflected because of incorrect definitions and methods used in data collection. These gaps will be addressed by a revision of methods used and an expansion of topics covered by surveys.