In BEA descriptions of quarterly estimates of services consumption, the phrase
“judgemental trend” figures prominently, particularly for early estimates. The phrase refers to a range of method less formal than standard NIPA methodology, which are used prior to the availability of actual data, and which experience indicates do not produce
systematic errors. Typically the judgemental trend applies to changes in quantities, while
components of the CPI (which are rapidly available) are used to estimate price change.
For example, early estimates of housing services are based on a judgemental trend for the housing stock, combined with actual data on rents from the CPI. For a number of service categories, quantity change is estimated using employment change in the industry
providing the service.

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Note added at 40 mins (2005-12-11 20:43:13 GMT)
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http://www.bea.gov/bea/an/nipaguid.pdf
NIPA is the "National Income and Product Accounts".