The broad goal of the project is to catalyze research in infectious disease epidemiology and to improve the related practice of disease control. The project will use the methods of service-oriented architectures and ontologies to build an informatics' infrastructure that will enable MIDAS researchers to develop larger and more complex models and larger and more capable systems. The project itself will use the same methods to develop an ontology-based information management system that will index datasets, publications, existing models, and computer-interpretable information-the 'raw materials' of modeling. The project will also employ informatics methods from the field of knowledge representation to construct a library of computer-interpretable information that can be re-used. The re-use of information will enable the construction of potentially ecosystem-size models. The project will also provide non-computational services in support of software engineering, model validation, dataset acquisition and meeting logistical support for the MIDAS network. The specific aims of the project are to: (1) Develop software for end users ranging from modelers to decision makers; (2) synthesize populations and environments for use by modelers; (3) significantly extend a prototype Apollo Library of standardized computable information; (4) significantly extend an ontology-based Information Management System; (5) create an "On Demand" High Performance Computing service; and (6) play other catalytic roles expected of the informatics resource, including logistical support, data acquisition, model validation, software engineering and quality control. The expected impact of the improvements of information management will be an acceleration of the research cycle. Overall, the project's impact on practice is that state and federal officials with responsibility for disease control will routinely utilize the developed software and services when formulating policy and making decisions, thereby increasing significantly the value of the science of infectious disease epidemiology to society.