A Summary and Commentary on D. and S. Premack’s Original Intelligence

The Analysis of Verbal Behavior -     

On-line bin packing with restricted repacking

Semi-on-line algorithms for the bin-packing problem allow, in contrast to pure on-line algorithms, the use of certain types of additional operations for each step. Examples include repacking, reordering or lookahead before packing the items. Here we define and analyze a semi-on-line algorithm where for each step at most k items can be repacked, for some positive integer k. We prove that the upper bound for the asymptotic competitive ratio of the algorithm is a decreasing function of k, which tends to 3/2 as k goes to infinity. We also establish lower bounds for this ratio and show that the gap between upper and lower bounds is relatively small.     

Social Networking and Individual Perceptions: Examining Predictors of Participation

Social networking is a process and practice that draws people and organizations together in an electronic medium. This article explores social interaction-based theories to suggest a social networking participation model that may help organizations understand acceptance or rejection of participation. Responses from 191 public administrators were analyzed using structural equation modeling (SEM), focusing on relationships between participation and five constructs: perceived usefulness, perceived ease of use, perceived improvement potential (PIP), intra-organizational trust, and type of use. The study found favorable model fit statistics that support positive correlations between the latent variables examined and participation in social networking activities. The results demonstrate the potential of the survey instrument to serve as an adoption and participation model to predict and promote social networking activities as they relate to perceived performance improvement.     

Harassment at the Workplace: A Practical Review of the Laws in the United Kingdom and the United States of America

Harassment is a major deterrent for productivity, loyalty, and commitment to one’s job and organization. Unfortunately, many employees tend to experience various forms of harassment in the workplace. The focus in this article is to understand the extent to which the law protects a person from harassment, first based on the explication and application laws in the United Kingdom. The article then provides comparative discussion of laws and practices against workplace harassment in the United States. A major objective of this article is to help employers and managers become more expert in preventing and correcting harassment.     

Flexible models for non-equidispersed count data: comparative performance of parametric models to deal with underdispersion

AStA Advances in Statistical Analysis - Count data as response variables are commonly modeled using Poisson regression models, which require equidispersion, i.e., equal mean and variance. However,...     

Community councils as a medium for public participation: a case study in Grampian region

Planning authorities in Scotland are obliged to consult the public before finalising policies and proposals to be included in their development plans. Community councils are intended to operate as ‘the voice of a neighbourhood’ and this paper analyses an attempt by a regional planning authority to use community councils as a vehicle for consulting the public in the preparation of a structure plan for a rural area. The paper concludes that the attempt was unsuccessful because the community councils were not clear about the role they were expected to play; nor were they adequately prepared for their role. The authors believe, however, that the involvement of community councils has potential for promoting greater public participation in the preparation of development plans.     

Unconstrained parametrizations for variance-covariance matrices

The estimation of variance-covariance matrices through optimization of an objective function, such as a log-likelihood function, is usually a difficult numerical problem. Since the estimates should be positive semi-definite matrices, we must use constrained optimization, or employ a parametrization that enforces this condition. We describe here five different parametrizations for variance-covariance matrices that ensure positive definiteness, thus leaving the estimation problem unconstrained. We compare the parametrizations based on their computational efficiency and statistical interpretability. The results described here are particularly useful in maximum likelihood and restricted maximum likelihood estimation in linear and non-linear mixed-effects models, but are also applicable to other areas of statistics.     

Using the EM-algorithm for survival data with incomplete categorical covariates

Incomplete covariate data is a common occurrence in many studies in which the outcome is survival time. With generalized linear models, when the missing covariates are categorical, a useful technique for obtaining parameter estimates is the EM by the method of weights proposed in Ibrahim (1990). In this article, we extend the EM by the method of weights to survival outcomes whose distributions may not fall in the class of generalized linear models. This method requires the estimation of the parameters of the distribution of the covariates. We present a clinical trials example with five covariates, four of which have some missing values.