Implemented as intended? Recording family worker activities in a Families First program

In evaluating family preservation services, it is important not only to study the service outcomes and the family characteristics, but also what actually happens during the treatment. This requires a program model. This article describes how a program model works, prescribes how workers should carry it out, and describes how researchers should measure the program's characteristics. The authors use data from Families First in The Netherlands to test the model. Results show that the method of the program meets the specified characteristics. The results are important for treatment, policy, education, and evaluation research.     

Business games and implementation research

This paper reviews some recent research in OR implementation and suggests that a new approach is required, which will take fuller account of the perceptions of managers concerned with the problem. Research games in business settings seem to offer a means for such approach. Some lessons learned from a business game used in this way are described and their implications for modelbuilders are discussed.     

Experience with a multi-year fleet planning model

The fleet planning problem requires determination of the changing airline fleet mix based on existing traffic levels and projected growth, on the existing fleet, various aircraft types available in the future, and other operational and financial considerations. Several applicable mathematical formulations have been reported. One of these has been programmed for the computer and used by the authors for several years. This paper discusses the application of that model to real airline planning situations. Such practical experience has effected changes in the program and the manner it is used in fleet planning studies.     

Ethnic Composition and School Performance in the Secondary Education of Turkish Migrant Students in Seven Countries and 19 European Educational Systems

This article examines the effect of the ethnic composition on school performances in secondary education for Turkish students, using both cross‐national and Swiss national PISA 2009 data. At the school level our results show no effect of the proportion of natives or the proportion of coethnics and a negative association between ethnic diversity (we employ a residualized score of diversity on the proportion of migrants) and math performances. Consequently, we find no evidence for social capital advantages and an indication of barriers. Finally, we find no association between social capital variables on national or educational system level and math performance.     

Hard and soft constraints in linear programming

The linear programme and its constraints are split into two parts. The first consists of the traditional structure, the second being akin to goal programming. SOFT constraints are weighted relative to each other and then approximately weighted relative to the HARD constraints. The LP is run four times giving different emphasis to the SOFT and HARD constraints. The manager requesting the LP has then to decide which gives the most appropriate solution.     

Economic lot disposition policies for single attribute sampling plans

Traditionally, single sampling plans have provided but two possible lot disposition policies, either to (1) accept or reject and screen, or to (2) accept or reject and scrap. This is particularly true of statistical designs. Economically based plans, however, provide a framework wherein several lot disposition policies may be invoked in accordance with estimated lot quality. This paper illustrates how such designs may be realized.