Spatial and contextual factors in human performance on the travelling salesperson problem

The travelling salesperson problem (TSP) provides a realistic and practical example of a visuo-spatial problem-solving task. In previous research, we have found that the quality of solutions produced by human participants for small TSPs compares well with solutions from a range of computer algorithm s. We have proposed that the ability of participants to find solutions refl ects the natural properties of human perception, solutions being found thro ugh global perceptual processing of the problem array to extract a best fig ure from the TSP points. In this paper, we extend the study of human perfor mance on the task in order to understand further how human abilities are ut ilised in solving real-world TSPs. The results of experiment 1 show that hi gh levels of solution quality are maintained in solving larger TSPs than ha d been investigated previously with human participants, and that the presen ce of an implied real-world context in the problems has no effect upon perf ormance. Experiment 2 demonstrated that the presence of regularity in the p oint layout of a TSP can facilitate performance. This was confirmed in expe riment 3, where effects of the internality of point clusters were also foun d. All three experiments were consistent with a global, perceptually based approach to the problem by participants. We suggest that the role of percep tual processing in spatial problem-solving is an important area for further research in both theoretical and applied domains.