An Experimental Comparison of Two Interactive Visualization Methods for Multicriteria Portfolio Selection

We compare two visualization methods for interactive portfolio selection: heatmaps and parallel coordinates. To this end, we conducted an experiment to analyze differences in terms of subjective user evaluations and in terms of objective measures referring to effort, convergence, and the structure of the search process. Results indicate that subjects who used the parallel coordinates visualization found the method easier to use, perceived the selection process as being less effortful, and experienced less decisional conflict than subjects who used the heatmap visualization. Concerning objective measures, we did not find significant differences in the time taken to complete the selection task. However, we found that subjects who used parallel coordinates engaged in a more exploratory approach when investigating the space of efficient portfolios. Finally, the experiments clearly showed that decision-making styles play an important role in users’ attitude toward the visualization method. Our findings suggest that the choice of visualization method has a considerable impact on both the users’ subjective experiences when using a decision support system for portfolio selection, and on their objective performance.