This study on verification, validation, and accreditation (VV & A) seeks, for military models and simulations, to (1) provide a simple and realistic framework for modelers, analysts, managers, and recipients of analysis; (2) address important complications that have received too little attention in the past (e.g., evaluation of knowledge-based models such as those representing command-and-control decisions and other behaviors); and (3) discuss how modern model-building technology is changing the way we should develop models and conduct VV & A. The study illustrates many of its suggestions about VV & A with specific examples of language that might be used in reports and accreditation reviews. It sketches elements of advanced modeling and analysis environments that would make such work easier.