Case study: the technology behind the 2011 census

Around 26 million households will complete the 2011 census in March, which will cost the government £482m to conduct.

Around 26 million households will complete the 2011 census in March, which will cost the government £482m to conduct. Kathleen Hall examines the technological deployments behind the country's largest information-gathering exercise and asks whether, in a data-rich age, such an operation is necessary.

A census for the 21st century

At 200 years old, the UK census has just received a facelift for the 21st century with a new online completion option and a postal tracking system - previously having been hand-delivered. Both aspects of the project have required a huge amount of technological deployments, says Ian Cope, director of census operations.

The census runs every 10 years: "The census is a bit like the Olympics, you only get one chance to get it right. So there needs to be lots of preparation and development as you can't do it again," he says.

Cope estimates that around 25% of those returning the form will complete it online, having looked at rates in countries that already offer this option. But with millions of people logging on for census day on March 27, the platform will need to be robust.

"It's not a case of how many people fill it in online, but when they access the website, so we've designed our platforms by looking at the profile of when people go online at the weekends. We've built capacity for more than 25% of people filling it online and if it proves to be more popular than expected the site will just ask people to come back later."

The technology behind the census

The online platform is built across two sites, with three layers of firewalls and an in-built design to withstand denial of service attacks. Cable & Wireless has provided the network infrastructure and Steria are conducting systems administration.

Validation tests and routing have also been built in, so if someone under 16 fills it out, the survey questions on employment will automatically be greyed out. "For a family of four we estimate it will take around 40 minutes, so it's quite quick and easy to fill in."

But while it is hoped the online option will take the strain off processing times, a considerable amount of investment has also gone into the technology behind postal returns.

The government has spent £6.2m on 10 high-speed scanners to scan each questionnaire in 0.25 seconds, a process estimated to take from March to December as 600 million sides of A4 are scanned.

The Royal Mail has also been equipped with flatbed scanners in 24 of its sorting offices, which immediately updates the address list of people yet to return their questionnaires so field staff don't waste time needlessly knocking on people's doors.

Once the census data has been captured, all the buildings, systems and equipment will be securely decommissioned or destroyed, in line with government standards. The data will be securely stored in Office of National Statistics' HQ in Titchfield. It has been agreed with the National Archive that the archive records will be microfilms of the census images (the paper questionnaires having been destroyed).

The future of the census

Cope says the census is the best way to inform local decision-making - such as businesses choosing where to locate shops, and libraries which books to stock. "Around £100bn from central government is given to health boards and local councils based on census information, so while it may cost around £500m, it's good value in terms of the benefit to national and local government.

"There's a new question which asks how much unpaid work you do as a carer, which will determine how many children might look after relatives, for example. That's not the sort of information you can get from a survey, it can only be provided through a census.

However, minister for the Cabinet Office, Francis Maude, said he hopes to save money by scrapping the census after this year. Cope says the Office for National Statistics is already looking at alternative ways of gathering information.

"Our focus is very much on 2011, but the ONS has kicked off a project beyond 2011, where we will be looking at ways we could collect data in a different way - but at the moment it's too early to speculate what that will be as we don't know what the world will look like in ten years," he says.

Given the preparation it takes to prepare for the census - Cope says he started planning around 2003 - and the government's drive to slash costs, this year may not only be the biggest but also the last ever census we complete.




The 2011 census: a necessary exercise?
Critics have pointed to alternative ways of collecting the information, which would amount to a fraction of current costs – such as collating statistics from existing data sets.
William Heath, digital rights campaigner, says that while some of the information from the census could be put to good use, the expense of the project is hard to justify and won’t yield results for two or three years. It also raises serious concerns about privacy issues, he says.
"It seems to me a clunky way of doing it, there are better, more contemporary ways of gathering information such as through social network sites - which would yield high penetration rates and cost a fraction of the price," he says.
Michael Parker, spokesman for privacy campaign group No2ID, agrees. "This is just a snapshot and because it takes so long to process it quickly becomes out of date," he says.
Douwe Korff, professor of international law at London Metropolitan University, says that under section 39 of the Statistics and Registration Service Act 2007, there could be circumstances when the data is shared. "While I am sure that the director of the census means it when he says the data will be kept confidential, there doesn’t appear to be any [legal] safeguards against privacy violations. There is a danger inherent in this exercise that in certain cases the database could be used to run profile checks to find suspects."



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