Informal User Interface For Natural Human-Computer Interaction

cess in applications where they have replaced humans in tasks at which humans are poor, such as performing complex, redundant mathematical calculations, or storing and searching large amounts of data. As computers grow more powerful, less expensive, and more ubiquitous, we begin to expect them to assist us in tasks that humans do well, such as writing, drawing, and designing. Many of these tasks involve creativity and communication, two activities that lie close to the heart of what makes us human. How to design computer systems to help humans do better at what they already do well is a problem that is far from solved. Unfortunately, the historical strengths of computers have led to a design bias towards support of precise computation, and away from the more human properties of ambiguity, creativity, and communication. Consequently, user interfaces today are designed to facilitate structured data input rather than natural human communication, which consists of the imprecise modes of spedung, writing, gesturing, and sketching. We use the term informal user interj5aces to describe user interfaces designed to support natural, ambiguous forms of humancomputer interaction. Sketching and gesturing are two modes of informal interaction that are especially valuable for creative design For designers, the ability to rapidly sketch ambiguous objects-those with uncertain types, sizes, shapes, and positions-is very important to the creative process. Ambignity encourages the designer to explore more ideas in the early design stages without being burdened by concern for inappropriate details such as colors, fonts, and precise alignment. At this phase, ambiguity also improves communication, both with collaborators and the target audience of the designed artifact. For example, an audience examining a sketched user-interface design will be inclined to focus on important issues, such as the overall structure and flow of the interaction, while not being distracted by the details of the look, such as colors, fonts, and alignmentk7 When the designer Computers have found their greatest suc-