On the conceptualization of theoretical constructs

An attempt is made to bridge the gap between the theorists and modellists approaches to the conceptualization of theoretical constructs. The former approach assumes that every theoretical construct has a surplus meaning over and above its operationalization and measurement as a concept. The latter approach denies this: it only accepts theoretical constructs as functions of relations between observations, i.e. measured concepts.This gap can be bridged by explicating the definition of a theoretical construct before making attempts to operationalize and measure it. An explicated definition should cover all relevant aspects (or: facets) of a construct, systematically brought together in an ideal type model. On this basis, operationalization of the construct can be directly linked to model elements, so that any possibly remaining surplus value is made explicit. The distance between theoretical construct and the measured concept can then be made as small as seems feasible; in principle, the distance can be made zero. The manner in which conservative ideology is conceptualized in a longitudinal research project in the Dutch electorate is presented as an example of this strategy.     

An extension of mixed estimation,with an application to forecasting new product growth

This paper extends the mixed estimation technique to handle a case in which the coefficients of a set of linear constraints are known nonlinear functions of an unknown parameter vector for which an extraneous unbiased estimate is available. This novel form of the mixed estimation technique is illustrated by applying it to the Bass innovation/diffusion model of new product growth. It is suggested that this is superior to the traditional method whereby managerial intuition is incorporated into this type of model, and is an attractive alternative to recently-suggested Bayesian methods.I thank an anonymous referee for helpful comments and references.     

Central sterile supply productivity and time study analysis

As a result of the productivity study in both areas, the following objectives can be attained: Ascertain the number of FTEs necessary for staffing requirements. Determine the efficiency level in daily production of trays and sets. Develop standards to measure the overall effectiveness in delivering service. Although this represents a quantitative analysis of the productivity within a CSS department, it is important not to forget the human element in the relationship between CSS and OR employees.     

Measuring cost savings in the operating room: a matter of FOCUS (follow-through, obsolescence, control, utilization, standardization)

In summary, changes came slowly at first in the OR. The biggest inventory reduction came about a year after the effort had begun. It would seem that tackling obsolescence, standardizing products, etc. would give an initial "big chunk" savings, with small amounts coming later as inventories are lowered. What we expected did not occur, due to the inherent nature of practices and what was customarily being used. For example, previously, some equipment purchases were paid for by purchasing product, which resulted in long-term commitments and high supply costs. The OR at times seemed more like a process of managing change, not just supplies. FOCUS is a daily process. How many times can you afford to overlook this process? How often are the mistakes of the past repeated? In review, we suggest this simple outline: Follow-through (review each case from start to finish), Obsolescence (schedule inventories every six months), Control (achieve inventory management by adjusting PAR levels to needs), Utilization (utilize product/equipment with your control), and Standardization (standardize products and measure results).     

L'approccio di B. De Finetti per la riassicurazione individuale proporzionale. Modelli semplificati e considerazioni operative

Viene studiato il problema della determinazione della strategia riassicurativa ottima in caso di riassicurazione individuale proporzionale, secondo l'approccio media-varianza. In particolare si analizzano alcuni modelli semplificati nei quali si raggruppano le polizze di un portafoglio sulla base di certe caratteristiche di omogeneità; ciò consente di ridurre in maniera sensibile la complessità dei calcoli previsti nella procedura generale. Completano il lavoro considerazioni di carattere operativo.

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Summary The optimal reinsurance strategy for the proportional reinsurance problem in a meanvariance framework is investigated. In order to simplify the algorithmic complexity, simple models based on the aggregation of portfolio policies are studied. Some operational remarks are added.