TL;DR: The ecological literature reveals considerable confusion about the meaning of validation in the context of simulation models, and disagreements over the mean can only be resolved by establishing a convention.
TL;DR: A framework that enables computer model evaluation oriented toward answering the question: Does the computer model adequately represent reality?
Abstract: We present a framework that enables computer model evaluation oriented toward answering the question: Does the computer model adequately represent reality? The proposed validation framework is a six-step procedure based on Bayesian and likelihood methodology. The Bayesian methodology is particularly well suited to treating the major issues associated with the validation process: quantifying multiple sources of error and uncertainty in computer models, combining multiple sources of information, and updating validation assessments as new information is acquired. Moreover, it allows inferential statements to be made about predictive error associated with model predictions in untested situations. The framework is implemented in a test bed example of resistance spot welding, to provide context for each of the six steps in the proposed validation process.
TL;DR: Recommendations for achieving transparency and validation are described, developed by a task force appointed by the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) and the Society for Medical Decision Making (SMDM).
Abstract: Trust and confidence are critical to the success of health care models. There are two main methods for achieving this: transparency (people can see how the model is built) and validation (how well the model reproducesreality).Thisreportdescribesrecommendationsforachieving transparency and validation developed by a taskforce appointed by the International Society for Pharmacoeconomics and Outcomes ResearchandtheSocietyforMedicalDecisionMaking.Recommendations were developed iteratively by the authors. A nontechnical description—including model type, intended applications, funding sources, structure, intended uses, inputs, outputs, other components that determine function, and their relationships, data sources, validation methods, results, and limitations—should be made available to anyone. Technical documentation, written in sufficient detail to enable a reader with necessary expertise to evaluate the model and potentially reproduce it, should be made available openly or under agreements that protect intellectual property, at the discretion of the modelers. Validation involves face validity (wherein experts evaluate model structure, data sources, assumptions, and results), verification or internal validity (check accuracy of coding), cross validity (comparison of results with other models analyzing the same problem), external validity (comparing model results with real-world results), and predictive validity (comparing model results with prospectively observed events). The last two are the strongest form of validation. Each section of this
TL;DR: In this article, a system, method and article of manufacture are provided for implementing presentation services patterns, where non-presentation logic executed on a client is assigned to an activity for allowing reuse of the non-Presentation logic across multiple, volatile user interfaces.
Abstract: A system, method and article of manufacture are provided for implementing presentation services patterns. Non-presentation logic executed on a client is assigned to an activity for allowing reuse of the non-presentation logic across multiple, volatile user interfaces. A view is assigned to the activity. Validation rules are also structured for validating user data across the multiple user interfaces.
TL;DR: Practical techniques and guidelines for verifying and validating simulation models are outlined and examples of a number of typical situations where model developers may make inappropriate or inaccurate assumptions are provided.
Abstract: In this paper we outline practical techniques and guidelines for verifying and validating simulation models. The goal of verification and validation is a model that is accurate when used to predict the performance of the real-world system that it represents, or to predict the difference in performance between two scenarios or two model configurations. The process of verifying and validating a model should also lead to improving a model's credibility with decision makers. We provide examples of a number of typical situations where model developers may make inappropriate or inaccurate assumptions, and offer guidelines and techniques for carrying out verification and validation.