Missing persons posters and billboards have had major changes made to them through science and technology to make them more memorable.

The charity Missing People hopes the changes will maximise the chance of the public engaging with the posters and taking action.

Examples of the changes and new features include having less information – which researchers suggest can sometimes bombard people – and featuring 3D images and smiling faces, which are considered to be more memorable and more likely to make an instant connection with passers-by.

After a decade of the old format, perhaps the most noticeable difference is the absence of the word “MISSING”.

Oxford Mail: Finn Layland-Stratfield's missing person billboard (Felicity Crawshaw/Missing Persons/PA)Finn Layland-Stratfield's missing person billboard (Felicity Crawshaw/Missing Persons/PA)

This has been replaced with the more active phrase “HELP FIND”, as according to research people are more likely to engage when presented with a clear call to action.

The new posters, which feature details of current missing people, will appear on billboards across London on May 25 to mark Missing Children’s Day and the new format will be used by the charity for all posters moving forward.

They also include a QR code to encourage passers-by to tap into social media and spread the word among their networks and background maps of where the person was last seen.

This is because people local to the area are more likely to respond to the call to action.

Some 70,000 children and young people are reported missing every year in the UK, and many more go unreported, according to Missing People.

Behavioural science consultant Anita Braga, who led the research, told the PA news agency: “Very often people do want to act, but they feel like they don’t have the means to, they feel a bit overwhelmed by the situation maybe, and so by telling them “help us” find rather than “missing”.

“Giving a clear call to action is a way to make them feel empowered and also feel empathy towards the person they’re looking for.

“And then the second thing is the image – we really worked on improving the image clarity and to give the feeling that there is actually a person behind that picture.”

Oxford Mail: Leah Croucher's missing persons poster (Felicity Crawshaw/Missing Persons/PA)Leah Croucher's missing persons poster (Felicity Crawshaw/Missing Persons/PA)

Ms Braga explained that her review of the available research found that having a clear call to action helps people feel less scared and overwhelmed, and more willing to act.

Mr Martin said: “Changing those words ‘missing person’ to ‘help us find’ turns that message from a passive one, into an active one, cuts through the everyday noise of information.

“And then clarifying and using some smart software to increase the definition of that image that is often a grainy, pixelated mobile phone image and making it much more clear.”

The faces of actual missing people are included in this campaign including Leah Croucher, who disappeared on February 15, 2019.

The other two children featured on the posters are Finn Layland-Stratfield and Alexander Sloley.

Finn was 17 when he went missing from Tintagel, Cornwall on July 8, 2017 while Alexander has been missing from Islington, London, since August 2, 2008, when he was just 16.