The notion of intentionality, the degree to which people go missing deliberately, has long been used as a framework to understand missing person incidents. Research about missing persons, across a range of disciplines, has developed a typology of ‘missing’ based around the concept of intentionality. Different approaches have been adopted, all of which have tried to encapsulate the ways that different ‘types’ of missing incident seem to suggest different levels of intentionality on the part of the missing person.