|dc.description.abstract||Architects and other visual thinkers create external representations of their ideas to support early-stage design. They compose visual imagery with sketching to form abstract diagrams as representations. When working with digital media, they apply various visual operations to transform representations, often engaging in complex sequences. This research investigates how to build interactive capabilities to support designers in putting together, that is phrasing, sequences of operations using both hands. In particular, we examine how phrasing interactions with pen and multi-touch input can support modal switching among different visual operations that in many commercial design tools require using menus and tool palettes—techniques originally designed for the mouse, not pen and touch.
We develop an interactive bimanual pen+touch diagramming environment and study its use in landscape architecture design studio education. We observe interesting forms of interaction that emerge, and how our bimanual interaction techniques support visual design processes. Based on the needs of architects, we develop LayerFish, a new bimanual technique for layering overlapping content. We conduct a controlled experiment to evaluate its efficacy. We explore the use of wearables to identify which user, and distinguish what hand, is touching to support phrasing together direct-touch interactions on large displays. From design and development of the environment and both field and controlled studies, we derive a set methods, based upon human bimanual specialization theory, for phrasing modal operations through bimanual interactions without menus or tool palettes.||