¹School of Computing, Napier University, 10 Colinton Road, Merchiston, Edinburgh, Lothian, EH10 5DT, UK

Correspondence: Martin Graham, E-mail: m.graham@napier.ac.uk; Jessie Kennedy, E-mail: kennedy@napier.ac.uk

^*Corresponding author.

Received 22 December 2008; Revised 3 July 2009; Accepted 23 July 2009; Published online 5 November 2009.

Abstract

This article summarises the current state of research into multiple tree visualisations. It discusses the spectrum of current representation techniques used on single trees, pairs of trees and finally multiple trees, in order to identify which representations are best suited to particular tasks and to find gaps in the representation space, in which opportunities for future multiple tree visualisation research may exist. The application areas from where multiple tree data are derived are enumerated, and the distinct structures that multiple trees make in combination with each other and the effect on subsequent approaches to their visualisation are discussed, along with the basic high-level goals of existing multiple tree visualisations.