Alison Pritchard, one of three deputies at the Office for National Statistics, admits it’s been odd to see how the ONS has been propelled into the limelight during the pandemic. In fact, so odd that only recently Pritchard was watching Richard Osman’s House of Games on the TV when a question popped up about the ONS. She remembers thinking: “Oh blimey, we’ve even made it onto quiz shows now.”

The ONS, headed by Sir Ian Diamond, is the largest independent producer of official statistics in the UK. While it may have only just appeared on many people’s radar, the institute has been collecting and publishing statistics related to the UK economy, population and society for 25 years. It conducts the census in England and Wales every 10 years and has offices in London, Tichfield (the Hampshire former home of the census) and Newport, “where there’s lots of staff with names I’m still learning to pronounce in Welsh,” says Pritchard.

Despite its long history, the work of ONS chiefs this year has arguably been more important than ever. In 2020 alone, the ONS released over 1000 publications, with analysis ranging from daily statistics on numbers of cases, weekly death tolls and the virus’ impact on unemployment to some lighter-hearted stats, like the vast number of people navigating the city on a bicycle during lockdown.

Analysis produced by the ONS has not only shaped our understanding of the pandemic, but also our response to it. The government relied heavily on this analysis – such as the ONS Covid-19 infection survey- to produce the roadmap out of lockdown.

But what is it actually like to work at the ONS, collecting data day in and day out, especially during a time of crisis?

As Pritchard admits, the pandemic has piled enormous pressure on the team: “The closer we move to the limelight, the more scrutiny there is. You’ve got to perform.”

Having previously headed the Government Digital Service -and dabbled in comedy writing on the side – she has worked as Director General for Data Capability at the ONS since October 2020. Her job is to “ensure that the organisation has both the data and the methodology to undertake its analysis and statistics.”

Over the past year, the team has worked at a frantic pace to provide an early picture of what’s been going on. Real-time data has been crucial for informing decision-making during the pandemic. Much of the ONS analysis that would normally be released annually has instead been “prepared within weeks”. This shift “has generated all sorts of challenges,” Pritchard says.

Multiple lockdowns have forced the team to think on their feet, and find brand new ways of gathering data. Instead of just relying on traditional survey-related information, the ONS has been making use of existing data from across government and industry – “data that is generated by the way people interact with services.” Payroll data from HMRC and data from online job sites, for instance, have given the Office an early insight into what is happening in the job market.

“Satellite imagery, as well as shipping and mobility information, have provided a much quicker snapshot of what’s going on in society as a whole,” says Pritchard. And anonymised location data from mobile phones has enabled the ONS to establish movement trends among the population during lockdown.

The Office has expanded this year – hiring many recruits with backgrounds in statistics, economics and data science – in order to cope with the heavy work load from Covid on top of the 2021 census.

But Pritchard insists that the pressure to work at pace to gather real-time statistics has never undermined the level of accuracy at which the ONS operates.

“I sit through many discussions with an incredible degree of dialogue around the nature of how we manage the statistical output”, she says. “We always take account of any potential biases in the data and we do everything we can to ensure we’re getting as large a collection across as diverse communities as we can.”

“The ONS’s reputation for accuracy has earned it public trust and this trust has always been the most important thing to the team”, she says. “It’s something we cherish.”

A common belief is that, “You can make statistics say anything you want them to.” When many share this sceptical stance, collecting data and producing analysis is only half the challenge. Next, you have to convince people that it’s reliable.

It’s not only through its commitment to accuracy that the ONS inspires public confidence. The team also works extremely hard to ensure that the nation’s data is kept securely. All of the data used is fully anonymised and aggregated. “We need to keep demonstrating to the public the lengths we go to in order to safeguard people’s data,” says Pritchard.

Another thing she is keen to stress is that all of the analysis produced by the ONS is “for the public good”. In general, she finds that people don’t mind sharing data as long as long as they can see it’s being used for their benefit. “So we need to keep demonstrating to people the value of our data collection and its ability to improve their lives.”

Take, for instance, the census; some people question why they have to fill it in. Her response to them: “You don’t complain when an ambulance turns up outside your door in a time of need, or when schools are available for your children in the right area. All that comes from generating knowledge about the country.”

The ONS has been independent of government since 2008. It doesn’t have a political agenda – it’s only, very clear, agenda is to make sure that policy decisions are data-driven. “Data needs to underpin the choices the government makes,” says Pritchard, “and we want to provide the data that can help it make those choices effectively.”

The pandemic has helped many to recognise the importance of data-driven decision-making. But something else that’s become especially apparent in the past year is the importance of combining data sets.

“There’s been a big cultural shift. Our departments are recognising that the data they hold actually has value beyond their own departmental boundaries. To be able to improve public services and evaluate the effectiveness of public policy, you have to bring the data together for the bigger picture.”

She cites Covid public health data as a clear example of how the ONS is “bringing together ever more sophisticated integrated data” – linking information from the Covid infection survey with vaccine information, census information plus GP and hospital data.

This cultural shift has occurred during a crisis but Pritchard hopes it will “translate into how we do things in a business-as-usual environment as well.”

The ONS is busy working on this. It has been chosen to lead the government’s Integrated Data Programme – a programme Pritchard describes as “the exciting future of how we are going to make data more usable for analysis across government.”

The team is working with the Department for Work and Pensions (DWP) and HMRC “to really emphasise the value of sharing the data more widely” – but, she hastens to add, “still in a safe and secure way.” When it comes to privacy matters, there will be all the same safeguards in place: “It won’t be a Wild West of data sharing across

The Integrated Data Programme is just one of many projects the ONS has lined up for the future. The team is also working with the Alan Turing Institute on generating synthetic data.

Synthetic data is data that is synthesised based on reality. “It’s still in its infancy”, says Pritchard, “but it’s becoming a really exciting area of focus.”

It will allow the team to take a small set of existing, real data, and use it to grow larger synthetic sets of much richer data. These larger sets can then be used to create statistics and analysis, and you can tackle the biases within them.

In the case of AI, it could be a game-changer. Synthetic data can provide a lot of the training data sets for use in machine learning algorithms, says Pritchard. “You have to train AI systems in order for them to operate effectively. The larger the data set, the better the training.”

“It may be a little hard to wrap your head around it but it’s a fascinating subject”, she says, “well worth a google”.

The past year has brought home to the nation as a whole the real need for data and statistics. And data analysts are among the unsung heroes of the pandemic.

The “data not dates approach” has been a turning point for ONS chiefs like Pritchard – “from gathering information in different ways, linking it up, working at pace, and positioning us in a place where we can bring real concrete value to policy-making.”

And, if we commit long-term to becoming a data-driven nation, then the relevance of their work is not about to fade anytime soon.

Be it synthetic or integrated, the ONS is set to drive data innovation well into the future. “Our combination of data is a very different thing than what it was two or three years ago,” says Pritchard, “and the ONS is pleased to say it feels like we’re on the front foot. But it’s moving very fast. We have to keep up with the new ways of thinking.”