Comparing the usability of grid-bag and constraint-based layouts

While the usability of GUI design methods has been studied in general, the usability of layout specification methods is largely unexplored. In this paper we provide an empirical comparison of two popular GUI layout models, grid-bag layout and constraint-based layout. While the grid-bag layout is a powerful layout model, the constraint-based layout is able to generate even more general and flexible layout configurations. We performed a controlled experiment with postgraduate students of Computer Science and Software Engineering, measuring efficiency, accuracy and preference for typical layout specification and editing tasks. The results show significant differences between both layout models: the initial specification of GUIs is faster with a grid-bag layout whereas editing of existing complex layouts is faster and more accurate with a constraint-based layout. The study shows that constraint-based layout, although it may seem more complicated at first glance, can compete with and in some cases even outperform more conventional techniques in terms of their usability.