George Karabatsos

Learn More
This research describes some of the similarities and differences between additive conjoint measurement (a type of fundamental measurement) and the Rasch model. It seems that there are many similarities between the two frameworks, however, their differences are nontrivial. For instance, while conjoint measurement specifies measurement scales using a(More)
In test analysis involving the Rasch model, a large degree of importance is placed on the "objective" measurement of individual abilities and item difficulties. The degree to which the objectivity properties are attained, of course, depends on the degree to which the data fit the Rasch model. It is therefore important to utilize fit statistics that(More)
Theories of decision making are often formulated in terms of deterministic axioms, which do not account for stochastic variation that attends empirical data. This study presents a Bayesian inference framework for dealing with fallible data. The Bayesian framework provides readily applicable statistical procedures addressing typical inference questions that(More)
A new statistical methodology is developed for the analysis of spontaneous adverse event (AE) reports from post-marketing drug surveillance data. The method involves both empirical Bayes (EB) and fully Bayes estimation of rate multipliers for each drug within a class of drugs, for a particular AE, based on a mixed-effects Poisson regression model. Both(More)
OBJECTIVE To determine whether depression in the elderly in institutionalized settings could be identified using the mood indicators in the Minimum Data Set (MDS) 2.0 (Section E1, Items A-P). DESIGN Descriptive study. SETTING Three nursing homes in the southeastern part of the country. PARTICIPANTS Residents aged 65 and above. MEASUREMENTS The items(More)
We present a scale to measure sexual risk behavior or “sexual risk propensity” to evaluate risk compensation among men engaged in a randomized clinical trial of male circumcision. This statistical approach can be used to represent each respondent’s level of sexual risk behavior as the sum of his responses on multiple dichotomous and rating scale (i.e.(More)
In a meta-analysis, it is important to specify a model that adequately describes the effect-size distribution of the underlying population of studies. The conventional normal fixed-effect and normal random-effects models assume a normal effect-size population distribution, conditionally on parameters and covariates. For estimating the mean overall effect(More)
The purpose of this investigation is to establish a unidimensional interval scale for measuring each country on the quality of higher education, based on indicators (items) characterizing various aspects of a country's quality. The data from these indicators are publicly available through the United Nations Educational, Scientific, and Cultural Organization(More)