This paper compares retrospective and prospective analyses of the effect of flip charts on test scores in rural Kenyan schools. Retrospective estimates suggest that flip charts raise test scores by up to 20% of a standard deviation. Yet prospective estimators based on a randomized trial provide no evidence that flip charts increase test scores. One interpretation is that the retrospective resul...

We have developed and evaluated a new procedure for detecting trends in quality-control measurements and applied it to laboratory data. The method requires the use of sequential or "moving" slope estimates to identify trends. Formulae are derived to estimate the regression error for the moving slope directly from the standard deviation of the analytical measurements obtained during characteriza...

PURPOSE This study was designed to evaluate the minimum interocular correlation (IOC) needed by the visual system to correctly perceive a static stereoscopic stimulus as a function of normal aging. It was also our goal to evaluate the feasibility of clinical charts testing this aspect of visual perception. METHODS Stereoscopic IOC threshold was determined in 100 normal observers (average age ...

BACKGROUND Intestinal helminths are often associated with poor growth and reduced physical activities, and may worsen already compromised nutritional status of children living in orphanages. AIMS To determine the relationship between intestinal helminthiasis and nutritional status of children living in orphanages in Benin City, Nigeria. SETTING AND DESIGN A cross sectional study carried out...

The Shewhart X¯- and S-charts are most commonly used for monitoring the process mean variability based on assumption of normality. However, many distributions may follow a positively skewed distribution, such as lognormal distribution. In this study, we discuss construction three combined jointly standard deviation. simulation results show that more effective when distribution is skewed. A real...

Electronic health record (EHR) systems are increasingly being adopted in pediatric practices; however, requirements for integrated growth charts are poorly described and are not standardized in current systems. The authors integrated growth chart functionality into an EHR system being developed and installed in a multispecialty pediatric clinic in an academic medical center. During a three-year...

Control charts are effective tools for signal detection in both manufacturing processes and service processes. Much of the data in service industries comes from processes having nonnormal or unknown distributions. The commonly used Shewhart variable control charts, which depend heavily on the normality assumption, are not appropriately used here. In this paper, we propose a new asymmetric EWMA ...

introduction: central nervous system develops during the first years of life. millions of synapses form among nervous cells before two years of age. the present research was performed to assess the effects of mothers’ training about complementary feeding and developmental skills on growth and development of 5-7 month infants referring to health centers in city of shiraz in southwest of iran. me...