Performing armchair roundoff analyses of statistical algorithms

Numerical stability is but one of many desirable properties which should be considered when designing statistical software. However, rigorous roundoff analysis is rarely done because it seems not worth the price; the influence of rounding error is usually of secondary importance, and the analysis is thought to be beyond the reach of all but a few specialists. This note discusses the role of roundoff analysis in the design of a statistical program and shows that new techniques sometimes make assessment of the effect of rounding errors no more difficult than the verification of other program properties.     

Žumberak: A Sixteenth-Century Refugee Settlement Zone

This article examines the movement of Orthodox Christian refugees from Bosnia to the Habsburg Monarchy in the 1530s and their settlement in a district called ?umberak. The movement of these Uskoks has never been examined in the context of refugee studies. This study of a refugee movement and settlement over a five-century period offers the possibility of reaching a better understanding of the long-term outcome of refugee movements. Ultimately, this article suggests that the refugees affected the land they settled as much as the settlement zone affected them, and that, in this case, the refugees were able to define their own outcome.     

Community Amenity Measurement for the Great Fly-Over Zones

The purpose of this paper is to provide an alternative operationalization of amenities that does not privilege certain kinds of natural resources and climatic conditions and that can be used for assessing the quality of life in small towns. The amenity inventory presented here extends previous literature by including a broad range of amenities (natural resource, indoor and outdoor built recreational facilities, public and private services, and downtown amenities). The community level of analysis and small town focus are also unique. The inventory uses both secondary data from public sources and primary data that can be gathered by researchers or community residents. Therefore, in addition to the scholarly contribution of the inventory, the process of defining and assessing community amenities may be a valuable tool for building interpersonal relationships within communities, generating community spirit, and developing strategies for enhancing the local quality of life.     

Civic Epistemologies: Constituting Knowledge and Order in Political Communities

How do we know things? The question of epistemology – which drives both the sociology and philosophy of science – is also a crucial question for political sociology. Knowledge is essential to even the most basic and foundational of political processes and institutions. In 2000, for example, the transition of power in the US presidential election hung for 36 days on uncertainty over a seemingly simple question of fact: who won the most votes in Florida? A few years later, disputed factual claims about Iraq's possession of weapons of mass destruction unraveled, calling into question key justifications of the US decision to invade Iraq in 2003 and significantly weakening perceived US legitimacy. Yet, surprisingly, sociologists and political scientists know relatively little about how knowledge gets made in political communities, nor how the making of knowledge is tied to other key aspects of political life, such as identity, authority, legitimacy, and accountability.     

Innovations in child protective services inservice training: commitment to excellence

The overwhelming obstacles to effective CPS intervention created by increasing reports of abuse and neglect, funding shortfalls, and the lack of qualified workers have prompted national efforts to reform the public child welfare system in the United States. Organizations such as the American Public Welfare Association, the Children's Defense Fund, the Child Welfare League of America, and the National Association of Social Workers are currently working closely with other national organizations to develop legislative proposals that will enable child welfare agencies to be more responsive to the needs of children and families. A critical component of this reform is the need to recruit, train, and retain qualified and competent CPS workers. The four training programs described in this article are examples of innovative programs seeking to enhance service delivery by enhancing the knowledge and skills of their staff members. Although the four programs were developed in very different political and social climates and within diverse organizational structures, they all provide useful lessons in how to develop efficient and effective training for workers delivering protective services for children. Any national, state, or local efforts to design and develop new CPS training programs should take into account the significant strides made by these agencies.     

Moments of Inertia and Graph Separators

Graphs that arise from the finite element or finite difference methods often include geometric information such as the coordinates of the nodes of the graph. The geometric separator algorithm of Miller, Teng, Thurston, and Vavasis uses some of the available geometric information to find small node separators of graphs. The algorithm utilizes a random sampling technique based on the uniform distribution to find a good separator. We show that sampling from an elliptic distribution based on the inertia matrix of the graph can significantly improve the quality of the separator. More generally, given a cost function f on the unit d-sphere Ud, we can define an elliptic distribution based on the second moments of f. The expectation of f with respect to the elliptic distribution is less than or equal to the expectation with respect to the uniform distribution, with equality only in degenerate cases. We also demonstrate experimentally that the benefit gained by the use of the additional geometric information is significant. Some previous algorithms have used the moments of inertia heuristically, and suffer from extremely poor worst case performance. This is the first result, to our knowledge, that incorporates the moments of inertia into a provably good strategy.