The ASA survey of graduate programs: Some problems with unproblematic responses

The most remarkable finding of the American Sociological Association’s first survey of graduate departments in sociology was the striking similarity among programs in terms of course requirements, the number of credits, thesis requirements, and other formal procedures that lead to the M.A. and Ph.D. Moreover, when asked to identify problems with their graduate programs, respondents were much more likely to mention the quality of students and the shrinking of budgets than the content or organization of their programs. The authors suggest that the apparent absence of problems may in itself be a matter of concern for the discipline.     

Periodic integration: further results on model selection and forecasting

This paper considers model selection and forecasting issues in two closely related models for nonstationary periodic autoregressive time series [PAR]. Periodically integrated seasonal time series [PIAR] need a periodic differencing filter to remove the stochastic trend. On the other hand, when the nonperiodic first order differencing filter can be applied, one can have a periodic model with a nonseasonal unit root [PARI]. In this paper, we discuss and evaluate two testing strategies to select between these two models. Furthermore, we compare the relative forecasting performance of each model using Monte Carlo simulations and some U.K. macroeconomic seasonal time series. One result is that forecasting with PARI models while the data generating process is a PIAR process seems to be worse thanvice versa.     

Necessary Edges in k-Chordalisations of Graphs

A k-chordalisation of a graph G = (V,E) is a graph H = (V,F) obtained by adding edges to G, such that H is a chordal graph with maximum clique size at most k. This note considers the problem: given a graph G = (V,E) which pairs of vertices, non-adjacent in G, will be an edge in every k-chordalisation of G. Such a pair is called necessary for treewidth k. An equivalent formulation is: which edges can one add to a graph G such that every tree decomposition of G of width at most k is also a tree decomposition of the resulting graph G. Some sufficient, and some necessary and sufficient conditions are given for pairs of vertices to be necessary for treewidth k. For a fixed k, one can find in linear time for a given graph G the set of all necessary pairs for treewidth k. If k is given as part of the input, then this problem is coNP-hard. A few similar results are given when interval graphs (and hence pathwidth) are used instead of chordal graphs and treewidth.     

“Nothing goes as planned”: Practitioners reflect on matching children and foster families

Matching children with foster carers is an important step in every nonkinship family foster care placement. Although guidelines for matching are provided in several studies, the case‐specific context of the decision can influence the practitioners' ability to adhere to these guidelines. Therefore, this study answers the following question: “How does the case‐specific context influence the practitioners' decision‐making process regarding matching in family foster care?” Using a qualitative design, 20 semistructured interviews were conducted with practitioners matching children with foster families. Three themes emerged representing different layers of practitioners' everyday decision‐making: matching as planned, matching being tailored, and matching being compromised. The results show that exceptions are part of practitioners' daily work, either due to the belief that it might benefit those involved or because of obstacles presented during the decision‐making process. When the decision is compromised, matching practitioners lower their standards, while at the same time safeguarding the quality of the match. This proves that matching in practice is more than choosing a family, and guidelines are needed to determine what “good‐enough” matching should entail.     

Strategic management in a firm of consulting engineers

This article describes the introduction of strategic management in a large and diversified company of consulting engineers in Brazil. This was done by a massive strategic planning effort in which the 60 top people of the company actively participated. This approach was chosen to produce both a comprehensive corporate strategy and strategic management capability throughout the company. The project therefore gave as much attention to training and guidance as to planning itself. Psychological, organizational and ‘political’ factors were taken seriously into account. Project management was a good joint-venture between some top people inside and some external consultants, strongly interacting with each other. The project resulted not only in plans, but also in decisions, including tidying-up the divisional structure of the firm. The article evaluates the project to determine success factors in such undertakings. It is interesting for managers to appreciate the factors involved in efforts to produce plans, develop managers and reorient a company at the same time. It is also interesting because it shows a fruitful, although demanding role for management consultants in strategic reorientations: more committed, more ‘on-line’ than experts submitting recommendations; less amorphous and more performance-oriented than organizational development gurus.     

A New Fully Polynomial Time Approximation Scheme for the Knapsack Problem

A fully polynomial time approximation scheme (FPTAS) is presented for the classical 0-1 knapsack problem. The new approach considerably improves the necessary space requirements. The two best previously known approaches need O(n + 1/³) and O(n · 1/) space, respectively. Our new approximation scheme requires only O(n + 1/²) space while also reducing the running time.