The 30th Turner prize will be contested by four artists who are almost impossible to pigeonhole, using techniques that include film, storytelling, installation and screenprinting.

The shortlist, announced on Tuesday at Tate Britain, is made up of Duncan Campbell, Ciara Phillips, James Richards and Tris Vonna-Michell.

All four are in a sense collagists, often using images and films they have physically discovered or found online. They also explore subjects that are more their parents' history than their own.