Statistics in Management Education

Results of two surveys are presented and indicate the statistical knowledge of past students from Master of Business Administration programmes, their usage of statistics together with their opinions about the statistical content of Master of Business Administration degree courses. These views are contrasted with the results of a second survey of academic staff who teach statistics on such programmes. We find that past students recommend a greater statistical content than is currently taught but, paradoxically, most of the academic staff associated with teaching the subject believe that the statistical content of their programme will decrease in future years.     

Commitment to care: managed care and child incarceration

Downsizing and managed care in the 1990s followed the psychiatric hospital scandals and closures of the 1980s. Many families are now unable to provide care for their troubled children. Childhood emotional or behavioral disorders have rapidly spread beyond the confines of the home into a community that has adopted a "zero tolerance" for crime. Intolerance for childhood criminal behavior has resulted in an explosion of children's prisons where, in the name of rehabilitation, many are finally receiving psychological help. This article discusses the decreased treatment of childhood psychiatric disorders and the increased admissions to children's prison facilities.     

Supplier involvement in product development in the electronics industry: A case study

The movement of activities earlier in the product development process requires a re-examination of the total supply network. The objective of this paper is to determine the degree of early supplier involvement (ESI) that exists between a multinational electronics company and its key suppliers, in terms of depth of integration, information exchange and buyer–supplier relationships. The paper provides insights into the strategic factors that affect the dynamics of the ESI process. The research indicates that there are considerable impediments for those participants responsible for establishing and managing the implementation of ESI. A number of strategic insights are identified that explain the existence of the impediments to the ESI process. Finally, based upon the findings a number of lessons are highlighted for organisations considering the adoption of the ESI process.     

Parents' Views on Social Work Interventions in Child Welfare Cases

Correspondence to Trevor Spratt, Lecturer in Social Work, School of Social Work, The Queen's University Belfast, 7 Lennoxvale, Belfast BT9 5BY, Northern Ireland. E-mail: T.Spratt{at}qub.ac.uk Summary This article reports findings from the third part of a three-partresearch project examining the potential for social workersto shift from a child protection to a child welfare orientationin their practice. Whilst social workers in the UK have beenencouraged to make such changes, they have been hampered byconcerns to manage risk. Findings reported from the earlierparts of the project, indicated that there was potential fora substantial proportion of child protection work to be redesignatedas child welfare work, but that where this was achieved in practice,there was evidence of the continued influence of child protectionprocesses as social workers sought to manage the risks inherentin child welfare cases. The study reported here sets out toascertain the views of parents who were subject to child welfareinterventions. The findings indicate that while parents feelapprehension with regard to contact with social workers, inthe majority of cases successful relationships are formed. Itis argued that social workers display considerable skill inmonitoring potential risks whilst engaging with families andthat the subtleties involved in such activity are not capturedby official measures of governance which concentrate on moreabstract indicators of performance.     

Quantile plots for mean effects in the presence of variance effects for 2k-p designs

In robust parameter design, variance effects and mean effects in a factorial experiment are modelled simultaneously. If variance effects are present in a model, correlations are induced among the naive estimators of the mean effects. A simple normal quantile plot of the mean effects may be misleading because the mean effects are no longer iid under the null hypothesis that they are zero. Adjusted quantiles are computed for the case when one variance effect is significant and examples of 8-run and 16-run fractional factorial designs are examined in detail. We find that the usual normal quantiles are similar to adjusted quantiles for all but the largest and smallest ordered effects for which they are conservative. Graphically, the qualitative difference between the two sets of quantiles is negligible (even in the presence of large variance effects) and we conclude that normal probability plots are robust in the presence of variance effects.     

A model for collaboration networks giving rise to a power-law distribution with an exponential cutoff

Recently several authors have proposed stochastic evolutionary models for the growth of complex networks that give rise to power-law distributions. These models are based on the notion of preferential attachment leading to the “rich get richer” phenomenon. Despite the generality of the proposed stochastic models, there are still some unexplained phenomena, which may arise due to the limited size of networks such as protein, e-mail, actor and collaboration networks. Such networks may in fact exhibit an exponential cutoff in the power-law scaling, although this cutoff may only be observable in the tail of the distribution for extremely large networks. We propose a modification of the basic stochastic evolutionary model, so that after a node is chosen preferentially, say according to the number of its inlinks, there is a small probability that this node will become inactive. We show that as a result of this modification, by viewing the stochastic process in terms of an urn transfer model, we obtain a power-law distribution with an exponential cutoff. Unlike many other models, the current model can capture instances where the exponent of the distribution is less than or equal to two. As a proof of concept, we demonstrate the consistency of our model empirically by analysing the Mathematical Research collaboration network, the distribution of which has been shown to be compatible with a power law with an exponential cutoff.