Introduction In epidemiologic research, it is essential to avoid bias, to control confounding and to undertake accurate replication. Bias, confounding and random variation/chance are the non-causal reasons for an association between an exposure and outcome. These major threats to internal validity of a study should always be considered as alternative explanations in the interpretation. Bias is ...

Institutions are governance tools. They are useful only if they impact on behaviour: of citizens, and of those administering the legal system. Models of behaviour are therefore crucial for institutional analysis and design. In light of this, this paper draws lessons for institutional analysis and design resulting from the models of multi-attribute decision-making assembled in this special issue...

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...

Randomized controlled trials (RCTs) are routinely used in medicine and are becoming more popular in economics. Data from RCTs are used to learn about treatment effects of interest. This paper studies what one can learn about the average treatment response (ATR) and average treatment effect (ATE) from RCT data under various assumptions and compares that to using observational data. We find that ...

Validity is an enduring theme in the information systems (IS) domain. However, because much of that discussion draws, at least nominally, on an Empiricist orientation, formulating issues of validity in a way that is pertinent to a practice-oriented discipline has been difficult. This is particularly true for external validity, which refers to the applicability, or relevance, of research to phen...

OBJECTIVE The Centers for Disease Control and Prevention's National Public Health Performance Standards Program (NPHPSP) has developed instruments to measure the performance of local and state public health departments on the 10 "Essential Services of Public Health," which have been tested in several states. This article is a report of the evaluation of the content and criterion validity of the...

Pintrich & De Groot, 1990). Motivational components include students' perceptions of the classroom environment as well as their self-related beliefs such as personal goals, self-efficacy, interest, and value beliefs. Cognitive components include students' content knowledge as well as various cognitive learning strategies such as rehearsal, elaboration, and organization, and metacognitive strate...

1. Background In the UK, the NIHR vision sees ‘more patients and health professionals participating in health research’ [1]. Fundamental to health research is the testing of interventions through RCTs. Achieving high participation in RCTs has traditionally been difficult. Published data show that a minority of RCTs recruit successfully [2,3]. Recruitment problems reduce the total recruited samp...