This paper investigates the connection between grade repetition and school dropout. Household data is matched against a panel of academic test scores and the school career of each child inferred from the combined dataset. The potential endogeneity of grade repetition is corrected for using the differences among teacher attitude to repetition as an instrument for grade repetition. The results sh...

BUILD-IT is an up-and-running system putting at work highly intuitive, videobased interaction technology to support complex planning and configuration tasks. It makes state-of-the-art computing and visualisation available to all kinds of users, without requiring any special computer literacy. Based on real, tangible bricks as M. Fjeld, K. Lauche, S. Dierssen, M. Bichsel & M. Rauterberg (1998): ...

We show that if P (x) is a polynomial with nondecreasing, nonnegative coefficients, then the coefficient sequence of P (x+ 1) is unimodal. Applications are given.

Previous analysis of CIREN and NASS data indicate the prevalence of anterior lateral loading to the occupant in side impact crashes. Numerous studies have examined the post mortem human subject (PMHS) response to pure lateral loading; however, the biomechanics of anterior lateral loads to the thorax are not well understood. The goal of this study is to develop a side oblique injury criterion an...

A method for establishing a minimum passing standard for a multiple choice test is described. The procedure is based on expert judgment about the content of test items. The method can also be used to monitor or adjust a standard that is already in place. The procedure carries advantages that are not available from other approaches to standard setting. It is easy to implement and easy for partic...

The decoherence mechanism signals the limits beyond which the system dynamics approaches the classical behavior. We show that in some cases decoherence may also signal the limits beyond which the system dynamics has to be described by quantum field theory, rather than by quantum mechanics. The problem of the range of applicability of quantum mechanics (QM) has been the object of much attention ...

Introduction At its heart, the process of validating pre-employment tests is all about amassing evidence demonstrating that a test score is related to a target job in some meaningful fashion that permits distinguishing between those who are likely to perform well from those who are not. As a result, in the truest sense of the word, it is not a test cannot be said to be valid or not valid but ra...

Discovering a generalized criterion that can predict the mechanical failure of various different structural materials is one of ultimate goals for scientists in both material and mechanics communities. Since the first study on the failure criterion of materials by Galileo, about three centuries have passed. Now we eventually find the "generalized energy criterion", as presented here, which appe...

A method is presented for proving primality and functional completeness theorems, which makes use of the operation–relation duality. By the result of Sierpiński, we have to investigate relations generated by the two-element subsets of A only. We show how the method applies for proving SÃlupecki’s classical theorem by generating diagonal relations from each pair of k-tuples.

In recent years much interest has focused upon Streptococcus mutans as the etiological agent of smooth-surface caries in both rodents (7, 8, 10) and humans (5, 11, 12). Although similar in many respects to other homolactic streptococci found in the oral environment, a nutritional characteristic which has been used to distinguish S. mutans is its ability to utilize either mannitol or sorbitol as...