Negotiated Project Engagements: Learning from Experience

How far is it possible to capture the lessons tobe drawn from successive projects that involveintervention by social scientists within or betweenorganizations, whether acting as researchers, asconsultants, as agents of change, or in some combination ofthese roles? This paper outlines the way in which aframework was developed, by staff and associates of TheTavistock Institute, for examining the varied and often subtle influences of successive“negotiated project engagements” on thedevelopment of wider personal, institutional, anddisciplinary programs. This framework is designed totake into account the contrasting perspectives of the investigatorsthemselves, of their organizational hosts, and of anyexternal sponsors whose primary concern will normally bewith project outcomes at a more generalized level. As an illustration, particular reference ismade to the experience of a pioneering project concernedwith policy-making in city government. This project wasundertaken to advance the understanding and practice of public planning, while also exploring thepotential for synergy between the perspectives ofoperational research and applied social science. Thepaper concludes with some speculations about thepotential for further developing this kind of frameworkin supporting experiential learning.     

Out of the Limelight: Discredited Communities and Informal Communication on the Internet

In this article we will suggest that print and related traditional media have been used more successfully in constituting a public sphere than in supporting more private and localized forms of community building (Habermas 1989; Stone 1991). The costs and control of print media, in addition to the stability of the content, have reduced the applicability of these media to the improvisatory and quotidian social processes that groups use to help keep themselves cohesive. In contrast, computer-based interactions have been and are being used extensively to support many of the informal interactions and related activities necessary to communities, giving members new tools for negotiating and rehearsing public forms of group life (Jones 1995). We hope to show how the public aspirations and problems of social groups shape their encounters with computers and encourage them to use computer interaction to manage their public representations.     

Automated Pricing Rules in Electronic Posted Offer Markets

Internet markets are heralded as enhancing efficiency by providing buyers and sellers with an abundance of information. In these electronic markets, firms have the opportunity to employ "pricebots," computerized algorithms that automatically adjust prices to prevailing market conditions. This article uses laboratory methods to examine the potential market impact of the endogenous selection of three automated pricing algorithms: undercutting, low-price matching, and trigger pricing. We find that the undercutting algorithm leads to prices similar to the game-theoretic prediction. Low-price matching generates significantly higher prices, and trigger pricing results in market prices below the game-theoretic prediction.     

The efficient cross-validation of principal components applied to principal component regression

The cross-validation of principal components is a problem that occurs in many applications of statistics. The naive approach of omitting each observation in turn and repeating the principal component calculations is computationally costly. In this paper we present an efficient approach to leave-one-out cross-validation of principal components. This approach exploits the regular nature of leave-one-out principal component eigenvalue downdating. We derive influence statistics and consider the application to principal component regression.     

A simple approximation relation between the symmetric generalized logistic and the students t distributions

In this paper, we obtain a new approximation of the Student's t distribution by using the symmetric generalized logistic (SGL) distribution function. The error of this approximation is shown to be 0(1/n² )where nis the degrees of freedom of thetdistribution. In comparison to similar approximations by George and Ojo and George et al. (1986), this new approximation is much simpler and more accurate. It is also shown that under some conditions, the tdistribution is a good approximation of the SGL distribution. Therefore, the complicated expressions for the cumulants and moments of the SGL can be approximated by those of the t, distribution. Finally, numerical results are given.     

Modern Food Supply Chains and Development: Evidence from Horticulture Export Sectors in Sub‐Saharan Africa

The global food system is undergoing rapid processes of transformation and modernisation. This is causing important changes in developing‐country food supply chains, particularly in supermarket‐driven and high‐value export chains, but the welfare implications of these changes are poorly understood. This article analyses and compares the welfare effects in different horticulture export chains in sub‐Saharan Africa, disentangling different types of effects and the channels through which rural households are affected. Its main conclusion is that increased high‐value exports and the modernisation of export supply chains can bring about important positive welfare effects, which can occur in various ways through product‐ or labour‐market effects and through direct and indirect effects.     

Vaccine Preventable Disease on Campus

Abstract

Vaccine preventable diseases (VPD) have declined as a cause of morbidity and mortality in the United States. From more than 500,000 cases of measles reported annually in the prevaccine era, there were only 1,436 cases reported in 1983 (38% on college campuses); from more than 12.5 million reported cases of acquired rubella and 20,000 cases of congenital rubella syndrome (CRS) reported in 1964, there were only 954 reported cases of rubella (an unknown number occurred on campuses) and 4 cases of CRS reported in 1983. Only 6 cases of diphtheria (1 occurred on a campus), 8 cases of paralytic polio, and 75 cases of tetanus were reported in 1983 in the United States.

While these declines have been dramatic, significant morbidity from these VPDs persist. Up to 25% of college age adults remain susceptible to measles and rubella. Most students would be eligible for their first booster (10 years after preschool dose) at the time of college entrance, 62% of young adults (18–39 years of age) are estimated to be susceptible to diphtheria, and 11% are estimated to be susceptible to tetanus. Fewer than 5% of young adults are believed to be susceptible to polio.

Measles and rubella continue to be associated with college outbreaks. All cases of measles and rubella should be reported to local health departments. College and universities have the opportunity to ensure the protection of their students, faculty, and employees by establishing and enforcing immunization requirements for measles, rubella, diphtheria, tetanus, and polio as a condition of matriculation, registration, or unemployment.     

Measles and Rubella on College Campuses: The Need to Act

Abstract

The lack of immunization requirements at the nation's colleges and universities threatens the maintenance of the interruption of indigenous measles in the United States. The high susceptibility rates in some college populations coupled with the high mobility of college students who may travel to countries where measles is endemic or epidemic increases the potential for measles outbreaks.

Preventing measles in college-age populations is particularly important because the disease can be more serious in adults. In view of the importance of preventing measles in college students, the Immunization Practices Advisory Committee (ACIP) of the U.S. Public Health Service has recommended that officials strongly consider immunization requirements for college entry.

The ultimate goal of rubella immunization is the protection of a future fetus against damage from intrauterine infection. Although rubella cases are reported routinely on college campuses, most colleges make no effort at controlling these outbreaks or instituting immunization requirements. The ACIP strongly urges educational institutions to require proof of immunity to rubella for registration or employment.     

Work–family conflict and stress: indications of the distinctiveness of role combination stress for Belgian working mothers

Research on the relation between work-family conflict (WFC) and stress focuses either on domain/role-specific stress (e.g. work stress), which is by definition and, operationalisation attributed to the respective role, or it focuses on ‘general’ stress, which can be a too broad or too general concept to measure stress related to WFC. This study introduces the concept of ‘role combination stress’ to indicate a stress that is more specifically related to the work-family role system and WFC than general and role-specific stress. The analysis of data on 429 Flemish working mothers shows that role combination stress is indeed a distinct type of stress.