The PADI Design System as a Complex of Epistemic Forms and Games

1. AERA April 2005 The PADI Design System as a Complex of Epistemic Forms and Games John Brecht SRI International

2. 2 Epistemic Forms & Games • Collins & Ferguson, 1993 • Epistemic forms - target structures that guide inquiry • Lists, hierarchies, causal analyses, systems dynamics models • Epistemic games - procedures for “filling out” a form • Entry conditions, constraints, moves, transfers • Dictate the epistemic nature of the resultant form

3. 3 EF&G – List making • Guides inquiries that have a set of answers • E.g. – What animals live in the desert? • Target form is… a list • Game • Examine raw data (say a book on deserts) • Add items to list according to constraints: • Similarity, coverage, distinctness, multiplicity, and brevity • Transfer if necessary (say to a hierarchy)

4. 4 EF&G – Object Modeling • Guides inquiries of the form • “What is the essential nature of X?” • “What are the features of X?” • “How does [complex object X] compare with [complex object Y]?” • Target form – Object model, a hierarchy of “objects” defined by properties and parent-child relationships • Game – 2 stages • Create class definition, a template for the features of come class of objects • Instantiate the class for various objects/domains/systems of interest

5. 5 Typical PADI Game • Start with some science standard or other motivating context • Examine Design Patterns library for guidance • Examine existing task Templates to see if an existing Template can be reused • Customize existing template or create new one; fill out all the slots • Typically done in groups • Sometimes begins with “reverse engineering” • Often calls for creation of a template hierarchy • “Finalize” a thoroughly completed Template – a Task Specification

6. 6 What is the epistemic nature of the PADI Design process? What new knowledge is created? • Principles of ECD “wired in” • Formal object model definition • Allows for component-wise comparison of different assessment designs • Reverse engineering to allow analysis of existing assessments • “Inheritance hierarchy” of templates shows viewer of broader “assessment landscape”