Eric Walkingshaw and Martin Erwig. Journal of Functional Programming, 2009.
Experimental game theory is increasingly important for research in many fields. Unfortunately, it is poorly supported by computer tools. We have created Hagl, a domain-specific language embedded in Haskell, to reduce the development time of game-theoretic experiments and make the definition and exploration of games and strategies simple and fun.
Martin Erwig and Eric Walkingshaw. IEEE Symp. on Visual Languages and Human-Centric Computing (VL/HCC'09), 23-27, 2009.
Continuing our research in explanation-oriented language design, we present a domain-specific visual language for explaining probabilistic reasoning. Programs in this language, called explanation objects, can be manipulated according to a set of laws to automatically generate many equivalent explanation instances. We argue that this increases the explanatory power of our language by allowing a user to view a problem from many different perspectives.
Paper (PDF, 270K)
Eric Walkingshaw and Martin Erwig. IFIP Working Conference on Domain Specific Languages (DSL'09), LNCS 5685, 310-334, 2009.
Experimental game theory is an increasingly important research tool in many fields, providing insight into strategic behavior through simulation and experimentation on game theoretic models. Unfortunately, despite relying heavily on automation, this approach has not been well supported by tools. Here we present our continuing work on Hagl, a domain-specific language embedded in Haskell, intended to drastically reduce the development time of such experiments and support a highly explorative research style.
In this paper we present a fundamental redesign of the underlying game representation in Hagl. These changes allow us to better leverage domain knowledge by allowing different classes of games to be represented differently, exploiting existing domain representations and algorithms. In particular, we show how this supports analytical extensions to Hagl, and makes strategies for state-based games vastly simpler and more efficient.
Paper (PDF, 208K)
Martin Erwig and Eric Walkingshaw.
IFIP Working Conference on Domain Specific Languages
(DSL'09),
LNCS 5685, 335-359, 2009.
Best Paper Award
We propose a new focus in language design where languages provide constructs that not only describe the computation of results, but also produce explanations of how and why those results were obtained. We posit that if users are to understand computations produced by a language, that language should provide explanations to the user.
As an example of such an explanation-oriented language we present a domain-specific language for explaining probabilistic reasoning, a domain that is not well understood by non-experts. We show the design of the DSL in several steps. Based on a story-telling metaphor of explanations, we identify generic constructs for building stories out of events, and obtaining explanations by applying stories to specific examples. These generic constructs are then adapted to the particular explanation domain of probabilistic reasoning. Finally, we develop a visual notation for explaining probabilistic reasoning.
Paper (PDF, 592K)
Eric Walkingshaw, Paul Strauss, Jon Mueller, Martin Erwig, Irem Tumer. ASME Intl. Design Theory and Methodology Conference (IDETC'09), 2009.
The design of hardware-software systems is a complex and difficult task exacerbated by the very different tools used by designers in each field. Even in small projects, tracking the impact, motivation and context of individual design decisions between designers and over time quickly becomes intractable. In an attempt to bridge this gap, we present a general, low-level model of the system design process. We formally define the concept of a design decision, and provide a hierarchical representation of both the design space and the context in which decisions are made. This model can serve as a foundation for software-hardware system design tools which will help designers cooperate more efficiently and effectively. We provide a high-level example of the use of such a system in a design problem provided through collaboration with NASA.
Martin Erwig and Eric Walkingshaw. IEEE Symp. on Visual Languages and Human-Centric Computing (VL/HCC'08), 101-108, 2008.
We present a visual language for strategies in game theory, which has potential applications in economics, social sciences, and in general science education. This language facilitates explanations of strategies by visually representing the interaction of players' strategies with game execution. We have utilized the cognitive dimensions framework in the design phase and recognized the need for a new cognitive dimension of "traceability" that considers how well a language can represent the execution of a program. We consider how traceability interacts with other cognitive dimensions and demonstrate its use in analyzing existing languages. We conclude that the design of a visual representation for execution traces should be an integral part of the design of visual languages because understanding a program is often tightly coupled to its execution.
Paper (PDF, 399K)