Data quality for denominator (population at risk) data, although often overlooked, can also be a problem.
Each center still needs clerks to type in data, although far fewer than for previous censuses.
The old policy required the explicit permission of users to share data, although this wasn't required by law.
He did not believe that Serco had benefited from altering the data, although the PCT's review was not complete.
Mr. Gioia said that Internet reading was included in the 2008 data, although the phrasing of the central question had not changed since 1982.
Most European countries, including Britain, do not require businesses or other entities to notify the public when they lose personal data, although some do so voluntarily.
"There are limitations to self-reported data, although we think it's a fairly good estimate of what's going on in New York, especially over time," she said.
He added that central bankers might not be swayed by a new batch of poor economic data, although there may be plenty on the way.
They do visualisations but you can also download large amounts of data, although for this you need to know the commodity codes you are interested in.
He claims poorly sited US weather stations could in theory be skewing temperature data, although a recent analysis using his data found this was not the case.
He said that other search companies, including Microsoft and Excite, had released similar data, although only to a select group of researchers.
