Visualizing Non-subordination and Multidominance in Tree Diagrams: Testing Five Syntax Tree Variants

In linguistics, it is quite common to use tree diagrams for immediate constituent analysis of sentences. Traditionally, these trees are binary and twodimensional. However, phenomena such as coordination and right node raising, have led to the view that a simple hierarchical approach of sentences is inadequate: some linguistic phenomena rather seem to involve non-subordination and multiple dependencies. The central question of the present research is this: what are workable alternative tree-like diagrams that can accommodate to this view? An experiment has been set up to test five different types of tree visualizations, including three-dimensional trees. Subjects were asked to respond to various questions concerning coordination and (non-constituent) right node raising constructions, and to mark their preference for each tree visualization. This paper will discuss the representation problems, and present the experiment and its results. It turned out that the tree most rich in information was the least usable one, whereas the tree, most close to the traditional syntax tree, but with colour enrichment, performed best.