They will explain how the proportion of monthly data will be increased and the planned methodological developments. Martin Weale from the National Institute of Economic and Social Research will be the discussant and will respond from the point of view of an external user of statistics. Martin is also a member of the Statistics Commission and will therefore also refer to issues of quality and reliability. Another element of the survey design was a panel management interview with a sample of workplaces interviewed in 1990. These innovations are widely regarded as successful, both as fieldwork operations and as providing a rich source of employer-employee data on a wide range of issues.
Evidence can also be available from trials of different designs.
In one such design the sequence of treatments is randomised - crossover trials. The problems commonly arise when the relevant estimates are not given. Based on work in progress with Francois Curtin, Doug Altman and Julian Higgins, methods will be described separately, depending on whether the data are continuous or binary, and whether or not there is any carryover. The 2001 censuses in the UK will, for the first time, include a strategy to control for underenumeration, which will permit estimates of underenumeration at all levels of aggregation. The development of this strategy has been the result of an integrated programme of research between all three UK censuses.