“I never guess. It is a shocking habit, destructive to the logical faculty,” said Mr Sherlock Holmes, Sir Arthur Conan Doyle’s famed fictional detective.

Data visualisation is now taking the guesswork out of planning in government, making it easier for officials to understand trends and patterns through images.

This has helped cities such as New York target problems in public safety, while Medellin has used it to meet the Sustainable Development Goals. It has also informed policymakers and the public in Australia, and the European Union has used the approach for environmental policies.

Here are four examples of how data visualisation is giving insights to governments around the world.

New York City – Public Safety

“For those committed to stopping gun violence, the next question must be where the gun comes from,” according to the New York Attorney General’s office.

The city has come a long way from its grisly past, but gun violence still remains a problem in the city. The New York Attorney General office is staring the gun down in the barrel by tracking firearms used in crimes in the city to prevent future crimes.

The project collated information from guns recovered from crime scenes to track their movement across the United States. This enables law enforcement officers to create better policies and strategies by having a clearer picture of the movement of illegal firearms in and out of the city.

Australia – Communicating health and welfare policies

The Australian Institute of Health and Welfare wants data to inform national discussions and policies. It is using visualisation tools to make numbers and statistics more accessible by showing how policies are making measurable impact.

The ease of using data visualisation to communicate has also sparked innovation in the independent statutory agency. Within the first year it was introduced, 6,000 visualisations were created internally, and 1,500 were shared publicly.

National health and social statistics – on its own – are often mind boggling to the broader public. For ground-up policymaking to be successful, the public needs access to data that tells a story, so they are empowered to give meaningful feedback.

Europe – Monitoring air pollution

The European Environment Agency is not holding its breath when it comes to tackling air pollution. It is tracking individual pollutants across all 28 member state to measure air quality standards over a period of more than ten years.

The World Health Organisation says air pollution is a leading cause of death worldwide, resulting in more than four million deaths this year. The European Environment Agency wants to eliminate that risk by reducing emissions and setting limits and target values for air quality. The data map allows countries to check their progress and empowers citizens to hold governments accountable if targets are not met.

Meanwhile, air pollution is a perennial problem in Southeast Asia. From the year-long smog from car exhausts choking the streets of Bangkok, to the yearly toxic cocktail of haze that blankets the region from Indonesia’s peat burning, and ASEAN could use a similar tool to track its progress on air quality for greater accountability.

Medellin – Tracking Sustainable Development Goals

The second largest city in Colombia, Medellin, is using data visualisation to see how it is faring on the 17 UN Sustainable Development Goals (SDGs.) There are 232 unique indicators under the SDGs. Medellin is tracking these to make sure they hit the 2030 target set by the United Nations.

The hometown of Pablo Escobar was named as the Lee Kuan Yew’s city of the year in 2016, for its transformation from one of the world’s most violent cities, to becoming a model for urban innovation. And data is playing a big role in demonstrating the technical feasibility of projects and getting citizens to support them.

Governments hold an ocean of data across all sectors and agencies. These data, if presented meaningfully, can be used to budget for long term policies in the government.

In a world full of data, visualisation may just “point of obvious things which nobody by any chance observes,” according to Holmes.

This article was produced in partnership with Tableau, a data analytics platform company.