Summary: | Until now, attempts to extend the one-way constraint evaluation model of the
spreadsheet paradigm to support complex objects, such as colored circles or user-defined
types, have led to approaches featuring either a direct way of creating objects
graphically or strong compatibility with the spreadsheet paradigm, but not both. This
inability to conveniently go beyond numbers and strings without straying outside the
spreadsheet paradigm has been a limiting factor in the applicability of spreadsheets. In
this thesis we present a technique that removes this limitation, allowing complex objects
to be programmed directly--and in a manner that fits seamlessly within the spreadsheet
paradigm--using direct manipulation and gestures. We also present the results of an
empirical study which suggests that programmers can use this technique to program
complex objects faster and with fewer errors. The graphical definitions technique not
only expands the applicability of spreadsheet languages, it also adds to their support for
exploratory programming and to their scalability. === Graduation date: 1997
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