Instrumental variables regression (IV regression) is a method for making causal inferences about the effect of a treatment based on an observational study in which there are unmeasured confounding variables. The method requires one or more valid instrumental variables (IVs); a valid IV is a variable that is associated with the treatment, is independent of unmeasured confounding variables, and h...

In symbolic data analysis, high granularity of information may lead to rules based on a few cases only for which there is no evidence that they are not due to random choice, and thus have a doubtful validity. We suggest a simple way to improve the statistical strength of rules obtained by rough set data analysis by identifying attribute values and investigating the resulting information system....

Readers of medical literature need to consider two types of validity, internal and external. 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. Selec...

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...

conclusions the results showed that acupressure is a safe technique and leads to cervical ripening. thus, regarding the desired results that were achieved when mothers applied acupressure themselves, it could be suggested that it is beneficial for mothers to be trained to apply this method at home. results there was a significant difference between mothers’ educations in the three groups. most ...

This paper employs meta-analysis to determine the influence of computer-based scaffolding characteristics and study and test score quality on cognitive outcomes in science, technology, engineering, and mathematics education at the secondary, college, graduate, and adult levels. Results indicate that (a) computer-based scaffolding positively influences learning (g = 0.53), (b) studies with zero ...

The objective of this paper is to describe empirical studies evaluating the impact of reference pricing interventions in pharmaceutical markets, and to assess the quality of their evaluation method. A total of ten studies were included in the review. The nature of the intervention, the nature of the data available, the nature of the question to be answered, and the requirements of the evaluatio...