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The gap between scientific knowledge and real world practice continues to be a major conundrum for the behavioral sciences. This paper briefly reviews the development of behavioral research and describes problems that have arisen in meeting the goal of improving behavioral interventions through science. Based on published literature and personal observations, the authors argue that behavioral r...

...........................................................................................1 LIST OF ABBREVIATIONS .....................................................................2 ORIGINAL ARTICLES.............................................................................3 PROLOGUE ...........................................................................................4 BACKGROUND......

The paper provides a first survey of the literature on external validity, using as a starting point recent debates regarding the use of randomized evaluations to inform policy. Besides synthesising contributions to the programme evaluation literature we consider definitions of external validity from other sub-disciplines within economics, such as experimental economics and the time-series forec...

Commercial truck driver Hours-of-Service (HOS) rules are periodically revised to reduce driver fatigue and improve driver health in costefficient ways. HOS research must demonstrate causal relationships between HOS parameters and important safety outcomes. Thus, two scientific requirements are internal validity (demonstration of true cause-effect relationships) and external validity (generaliza...

Readers of medical literature need to consider two types of validity, Internal and extemal. Internal validity means that the study measured what it set out to; external validity Is the ability to generalise from the study to the reader's patients. With respect to internal validity, selection bias, information bias, and confounding are present to some degree in all observational research. Select...

Much of the methodological discussion around experiments in economics and other social sciences is framed in terms of the notions of internal and external validity. The standard view is that internal validity and external validity stand in a relationship best described as a trade-off. However, it is also commonly held that internal validity is a prerequisite to external validity. This article a...

CONTEXT The transition to retirement has been recognized as a turning point in determining physical activity and may present a critical "window" for promoting physical activity. This systematic review examined changes in physical activity across the retirement transition, whether these changes vary by SES, and what is known about predictors of these changes. EVIDENCE ACQUISITION Peer-reviewed...