A curtailed test for the shape parameter of the Weibull distribution

Summary A procedure is proposed in this paper for testing the shape parameter, of the Weibull distribution. The test statistic which is based on the extremal quotient, possesses a monotone property which makes it possible for rejection earlier than the last planned observation of the null hypothesis,H ₀: =₀ when the alternative hypothesis isH _a: <₀ and early acceptance ofH ₀ whenH _a: >₀. The test being scale-free, does not require the scale parameter to be known.     

Developing a tutoring module for presentation of computerized patient management problems

The simulation problem is one of the most commonly used formats in computer-assisted instruction (CAI). In medical education, a patient simulation problem is known as a patient management problem (PMP). A number of computerized PMP systems are currently available. However, to date, there is no record of PMP systems having been developed using artificial intelligence. This is noteworthy since artificial intelligence techniques could help in the generation of more effective and intelligent instructional systems.

This paper analyzes and evaluates existing instructional simulation software in clinical medicine in terms of effective educational design attributes. Components of effective PMP systems thus identified are incorporated into a computerized instructional system which uses artificial intelligence techniques for teaching problem-solving and diagnostic skills to undergraduate medical students.     

FLEXIBLE MANPOWER RESOURCING: A LOCAL LABOUR MARKET SURVEY

This article presents the results of an establishment level investigation carried out late in 1986 and early in 1987 of the extent of flexible manpower resourcing in the Aberdeen local labour market. It is necessary to place these results in the context of the general background of an increasing interest in flexible manning and of certain theoretical developments in labour and industrial economics. The results suggest that whilst a variety of means are used to attain flexibility in manning, few establishments can be regarded as truly ‘flexible firms’ and manpower strategies tend to be largely reactive and ad hoc.     

An optimum sampling design to base HT-method of estimating a finite population total

The problem of constructing a sampling design with the value of the sum of second order inclusion probabilities attaining its lower bound for non-integral values of the expected effective size of a sample in the design has been considered in this paper. If the values of the characteristic of interest on all the units in the population are non-negative the design is admissible (in the sense of variance) with respect to Horvitz-Thompson estimator in the class of designs with the same set of values of the first order inclusion probabilities of the units. Again such a design is best to use Horvitz-Thompson estimator of population total in the sense of smallest average variance of the estimator under a special superpopulatio model.     

Social distance and shopping behavior

This research was designed to see whether a reconceptualization of social distance (as measured by social class variables) between shoppers and stores would provide a basis for understanding store avoidance behavior. A survey of shoppers classified into two distinct social classes investigated their images, including social class images, of two stores that had been selected as representatives of upscale and downscale retailers. A new measure of social distance was proposed and evaluated. Controlling for other functional aspects of store image such as price and personnel, the social distance measure was found to be influential in discriminating shopping frequency groups for the two stores, providing evidence that people tend to avoid stores that are perceived as being socially distant from themselves.     

The effect of interstate highway on driving times and regional shopping center drawing power

Previous studies of the driving times of shopping center patrons have not examined the effect of limited access highways. This study analyzed the impact of interstate highways on the driving times of 204 shoppers at three medium-sized regional shopping centers. Those shoppers indicating usage of interstate highways to reach their shopping destinations were significantly more likely to incur travel times greater than fifteen and twenty minutes than those not using the available interstate roads. In predicting the drawing power of these shopping centers, factors besides mass were found to be useful. These include square footage of shopping goods, stores, and number of parking places.     

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.