Rossano Barone

Opening the Information Bottleneck in Complex Scheduling Problems with a Novel Representation: STARK Diagrams

This paper addresses the design of representational systems for complex knowledge rich problems, focussing on scheduling in particular. Multiple tables are ubiquitous in representations of schedule information, but they impose large cognitive demands and inhibit the comprehension of high-level patterns. The application and evaluation of representational design principles in the development of STARK diagrams, a novel system for scheduling problems, is reported. STARK diagrams integrate conceptual dimensions, principal relations and individual cases into a single diagrammatic structure. An experiment compared performance on STARK diagrams and a conventional representation with features typical of current commercial scheduling software interfaces. Subjects using the STARK diagram performed better at improving an examination schedule by minimising constraint violations. This provides support for the validity and utility of the design principles.

Representations for problem solving: on the benefits of integrated structure

How should problem-solving representations for complex knowledge domains be designed? Traditional approaches typically address the problem of semantic complexity by designing systems that offer multiple and often heterogonous forms of representation. The REEP approach advocates structure preserving integration of the different classes and perspectives of a domain within a single representation. This work reports on a novel representational system for nurse rostering that was designed under the REEP approach. An empirical evaluation suggests the kinds of knowledge support provided by the representation and demonstrates that participants prefer fully integrated over selective views of information even though the former increases visual complexity. This knowledge support is explained in terms of more abstract domain independent cognitive benefits that we present as reasons for adopting the REEP approach.

Representing Rosters: Conceptual Integration Counteracts Visual Complexity

STARK-Roster is a novel diagrammatic interface for a complex rostering problem. It may overcome the problems caused by the inevitable visual complexity of interfaces for such a complex domain. It encodes the inherent conceptual structure of the personnel scheduling task using a globally coherent and transparent representational scheme. This further demonstrates the utility of the RepresentationalEpistemological Interface Design approach.

Cognitive and Semantic Perspectives of Token Representation in Diagrams

The article considers a perspective on token representation in diagrams and its relation to other properties typical of diagrammatic external representations (ERs). We distinguish between direct and indirect cognitive modes of token reference based on whether a referential attribute of ER tokens, represented by a cognitive system, is used as a surrogate for represented tokens. We then consider how this characterization sheds light on particular cognitive properties of representing objects and relations in diagrams and diagrammatic kinds of engagement with sentential classes of ER.

Interpreting Lines in Graphs: Do Graph Users Construe Fictive Motion?

A pilot study was designed to investigate the plausibility of construing fictive motion from function lines in Cartesian graphs.Participants (n=18) were presented with a series of lines graphs and required to judge which of two lines of expressed the greatest rate of change in the value of Y.Some of the graphs had arrows pointing in a direction of the line that was either consistent (consistent condition) or inconsistent (inconsistent condition) with change progressing from the origin of the horizontal axis.Graphs in the neutral condition had no arrows.It was hypothesized that if users construe fictive motion when interpreting change of function lines then (a) inconsistent arrows should detrimentally interfere with the judgments and (b) consistent arrows should facilitate the judgments.Results were as predicted.Response times in inconsistent trials were slower than the neutral condition and for consistent trials response times were faster than the neutral condition.