Ambiguous intentions: a Paper-like Interface for creative design

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Daniel's bog

Summary

In this paper the author discusses a pen-based interface that acquires information about ambiguity and precision from freehand input, represents it internally, and echoes it to users visually and through constraint based edit behavior.

In this paper the author speaks about sketch interface Electronic Cocktail Napkin and its support for abstraction, ambiguity and imprecision. Abstraction is letting symbol takes the place of a more detailed configuration of parts, enabling a designer to work with components without specifying their internal structure. Ambiguity is to postpone the commitment yet retain a marker for a later decision. Imprecision permits postponing decisions about exact dimensions and positions.

Napkin allows users to draw as they would do on a paper e.g. harder pressures cause the brush instrument to display thicker line etc. Napkin also tries to recognize glyphs the user draws, and it may echo this recognition by displaying the name of the glyph. Napkin also allows configuration definition and recognition e.g. it allows the user to draw a configuration of dining table and chairs and mark this configuration with a letter ‘D’ inside the box. The configuration of dining room is abstracted with ‘D’ inside the box. Napkin’s configuration works as daemons and would try to recognize the configuration if there is a pause of 5 seconds in user drawing. Napkin also represents imprecision with internal constraint representation. Napkin identifies spatial relation among drawing elements and asserts them as constraints on the drawing. It also allows the user to modify, add, and delete the constraints identified by Napkin.

For the implementation of Napkin there is a low level recognizer which helps in the recognition of glyphs. It does it by maintaining a 3x3 grid and keeping Hash map for the pen-path. It also assigns each input glyph with confidence values. The user is also allowed to enter new glyphs on the fly by drawing them and assigning it a name. Recognition of configuration is done through recognizer functions which look over all pairs of appropriately typed elements in the diagram of these patterns. New configurations can also be added by drawing a configuration and napkin automatically extract constraints from the diagram (the user can also edit these configurations).

The system was tested out by undergraduate students, architects and design students. Most designers have understood and appreciated the need for end-user training of symbols and contextual definition of configurations.

Discussion

Napkin is an exciting system which does a lot high-level contextual recognition and definition by I think it's low level recognizer is not very strong. I seems to work with simple and small gestures, but the idea of resolving ambiguity through contextual information is really interesting.