Alan F. Blackwell

Learn More
Existing devices for communicating information to computers are bulky, slow to use, or unreliable. Dasher is a new interface incorporating language modelling and driven by continuous two-dimensional gestures, e.g. a mouse, touchscreen, or eye-tracker. Tests have shown that this device can be used to enter text at a rate of up to 34 words per minute,(More)
Research into the cognitive aspects of programming originated in the study of professional programmers (whether experts or students). Even “end-user” programmers in previous studies have often worked in organizations where programming is recognized to be demanding professional work – the term “power-user” recognizes this technical kudos. But as personal(More)
Most programs today are written not by professional software developers, but by people with expertise in other domains working towards goals for which they need computational support. For example, a teacher might write a grading spreadsheet to save time grading, or an interaction designer might use an interface builder to test some user interface design(More)
We describe extensions to the Excel spreadsheet that integrate user-defined functions into the spreadsheet grid, rather than treating them as a "bolt-on". Our first objective was to bring the benefits of additional programming language features to a system that is often not recognised as a programming language. Second, in a project involving the evolution(More)
The Cognitive Dimensions of Notations framework has been created to assist the designers of notational systems and information artifacts to evaluate their designs with respect to the impact that they will have on the users of those designs. The framework emphasizes the design choices available to such designers, including characterization of the user's(More)
People find it difficult to create and maintain abstractions. We often deal with abstract tasks by using notations that make the structure of the abstraction visible. Programming-by-example (PBE) systems sometimes make it more difficult to create abstractions. The user has to second-guess the results of the inference algorithm and sometimes cannot see any(More)
The Cognitive Dimensions of Notations framework (CDs) provides a powerful vocabulary for discussing the usability of programming languages, tools and environments. Although originally proposed as a discussion tool for designers, they have recently been used to design questionnaires intended for system users evaluating the usability of the programming tools(More)
Earlier research on gender effects with software features intended to help problem-solvers in end-user debugging environments has shown that females are less likely to use unfamiliar software features. This poses a serious problem because these features may be key to helping them with debugging problems. Contrasting this with research documenting males'(More)