A comparison of tests of homogeneity for sparse contingency tables

Five tests of homogeneity for a 2x(k+l) contingency table are compared using Monte Carlo techniques. For these studiesit is assumed that k becomes large in such a way that thecontingency table is sparse for 2xk of the cells, but the sample size in two of the cells remains large. The test statistics studied are: the chi-square approximation to the Pearson test statistic, the chi-square approximation to the likelihood ratio statistic, the normal approximation to Zelterman's (1984)the normal approximation to Pearson's chi-square, and the normal approximation to the likelihood ratio statistic. For the range of parameters studied the chi-square approximation to Pearson's statistic performs consistently well with regard to its size and power.     

Estimation of river and stream temperature trends under haphazard sampling

Long-term temporal trends in water temperature in rivers and streams are typically estimated under the assumption of evenly-spaced space-time measurements. However, sampling times and dates associated with historical water temperature datasets and some sampling designs may be haphazard. As a result, trends in temperature may be confounded with trends in time or space of sampling which, in turn, may yield biased trend estimators and thus unreliable conclusions. We address this concern using multilevel (hierarchical) linear models, where time effects are allowed to vary randomly by day and date effects by year. We evaluate the proposed approach by Monte Carlo simulations with imbalance, sparse data and confounding by trend in time and date of sampling. Simulation results indicate unbiased trend estimators while results from a case study of temperature data from the Illinois River, USA conform to river thermal assumptions. We also propose a new nonparametric bootstrap inference on multilevel models that allows for a relatively flexible and distribution-free quantification of uncertainties. The proposed multilevel modeling approach may be elaborated to accommodate nonlinearities within days and years when sampling times or dates typically span temperature extremes.     

Likelihood estimation for exchangeable multinomial data

In this article, maximum likelihood estimates of an exchangeable multinomial distribution using a parametric form to model the parameters as functions of covariates are derived. The non linearity of the exchangeable multinomial distribution and the parametric model make direct application of Newton Rahpson and Fisher's scoring algorithms computationally infeasible. Instead parameter estimates are obtained as solutions to an iterative weighted least-squares algorithm. A completely monotonic parametric form is proposed for defining the marginal probabilities that results in a valid probability model.     

Policy deployment: A case study analysis

Theaim of theresearch reported in thispaper wasto examine policy deployment in a business unit of the UK company operation of a major corporation, considered a world leader in business improvement. In this study, the application of policy deployment at an operational level was investigated to determine how managers deploy and manage direction, and assess the effectiveness of the catchball process. In the business unit studied, policy deployment could have a greater impact. For example, in deploying direction, cascade and catchball is used, however, the leadership, checks, control and communication elements could be more effective, and the respective shortcomings are described. A generic catch-reflect-improvescrutinize-pass (CRISP) approach to policy deployment is proposed by which vision, mission, goals, objectives, targets and means can be more effectively deployed.     

An Empirical Model of Growth Through Product Innovation

Productivity differences across firms are large and persistent, but the evidence for worker reallocation as an important source of aggregate productivity growth is mixed. The purpose of this paper is to estimate the structure of an equilibrium model of growth through innovation designed to identify and quantify the role of resource reallocation in the growth process. The model is a version of the Schumpeterian theory of firm evolution and growth developed by Klette and Kortum (2004) extended to allow for firm heterogeneity. The data set is a panel of Danish firms that includes information on value added, employment, and wages. The model's fit is good. The estimated model implies that more productive firms in each cohort grow faster and consequently crowd out less productive firms in steady state. This selection effect accounts for 53% of aggregate growth in the estimated version of the model.     

Basic Reading Through Dance program. The impact on first-grade students' basic reading skills

This study evaluates the effectiveness of an arts-based educational program, Basic Reading Through Dance. Basic Reading Through Dance is a 20-session, curriculum-based reading intervention for first-grade students developed by Whirlwind, a not-for-profit organization. There were a total of 721 first-grade students from Chicago public schools who participated in the study, with 328 students from 6 schools receiving the program and 393 students from 9 schools serving as controls. The program was designed to improve reading skills, as assessed by the PhonoGraphix Test, such as code knowledge (alphabet sounds) and phoneme segmentation (separating letter sounds within spoken words). Results suggest that the students who participated in the program improved significantly more than control students on all reading skills that were assessed.     

World slavery and Caribbean capitalism

Conclusion The perspective presented here constructs the distinct way in which land, labor, and technology in nineteenth-century Cuba were constituted within specific historical processes of the evolving capitalist world economy. Technological development had dynamic consequences for Cuba. There the availability of land, essential to the extensive pattern of exploitation of the Cuban sugar industry, was blocked by the difficulties of transport. Nevertheless, this limit - instead of becoming simply destructive and leading to a regression - led to the surpassing of the previous order: it resulted in a new social-economic form on which an accelerated rhythm was imposed with the introduction of the railroad, the integration of the island's economy into the world-scale circuits of capital, and the expansion and intensification of slave labor.To the degree that Moreno ignores the world historical character of Cuban slavery, he obscures what is distinctive about its local history. The apparent continuity of the history of slavery and slave emancipation and its seemingly singular relationship to capitalist development conceal the complex, multiple, and qualitatively different relations and processes constituting slavery within the world processes of capital accumulation and division of labor. Despite apparent similarities, the sugar plantation and slave labor in Cuba are not the same as in Barbados, Saint Domingue, or Jamaica. The latter represent a cycle of slave production that precedes industrial capital and the integration of world markets characteristics of the nineteenth century, whereas the organization of land, labor and technology in Cuba presupposes integrated world markets and capital circuits increasingly centered in industrialized production. The nexus of market and productive processes in these two socioeconomic situations result in sharply contrasting temporal differences. In Cuba, a structural change in historical time itself took place. (One might speak of the denaturalization of historical time, which can be grasped from the perspective of technology and industry.) The development of the sugar industry was characterized by movement, acceleration, and openess to new social-economic arrangements within and new spaces without. In this context, specific rhythms, sequences, and periods appear within a plurality of temporal strata of variable extension and duration that interact in the same historical dimension of modernity, and which can only be understood in relation to one another.Thus, instead of undertaking to apply abstract and general categories to the interpretation of specific processes, in this article I emphasize the need to adopt theoretical perspectives and methodological procedures that take as their premise the historical unity and specificity of the development of the capitalist world economy. Only in this way does it becomes possible to comprehend the complexity of slave relations - the ways in which they are both continually formed and reformed within the processes of world economy and contain within themselves conditions of modern economy and polity. Similarly, such an approach permits the world economy itself to be understood as the unity of diverse relations and processes, the modernity of which is defined not by the ever-increasing dominion of a homogeneous and one-dimensional rationality, but by its inherent complexity and historical unevenness.

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Development and Measurement Validity of a Task-Technology Fit Instrument for User Evaluations of Information System

Although many researchers have raised concerns about the lack of theoretical underpinnings for the user evaluation construct and the lack of measurement validity for specific instruments measuring it, the construct is still widely used in IS research. This paper reports on the development and measurement validity of a diagnostic tool used in recently published research to evaluate an organization's overall information systems and services. A distinctive feature of this instrument is that it is conceptually based on the task-technology fit theory in which the correspondence between information systems functionality and task requirements leads to positive user evaluations, and positive performance impacts. Specifically, the instrument development was guided by a task model of managerial decision making using recorded organizational information. This model suggested the different information systems functionalities required by users for that task, which then serve as the basis for a “task-technology fit” (TTF) instrument. The instrument thus measures the degree to which an organization's information systems and services meet the information needs of its managers. An extensive test of the measurement validity of the instrument is conducted using a sample of 357 users in 10 companies. It is found to have excellent reliability and discriminant validity for 12 dimensions of TTF, and also exhibits strong predictive validity. Finally, the instrument is compared to two other well-known user evaluation instruments. Though no single instrument can meet all needs, the instrument presented here should be considered an attractive option for researchers and practitioners seeking to measure the effectiveness of organizational information systems.     

Using process evaluation to determine effectiveness of participatory ergonomics training interventions in construction

The construction industry continues to experience high rates of musculoskeletal injuries despite the widespread promotion of ergonomic solutions. Participatory ergonomics (PE) has been suggested as one approach to engage workers and employers for reducing physical exposures from work tasks but a systematic review of participatory ergonomics programs showed inconclusive results.. A process evaluation is used to monitor and document the implementation of a program and can aid in understanding the relationship between the program elements and the program outcomes. The purpose of this project is to describe a proposed process evaluation for use in a participatory ergonomic training program in construction workers and to evaluate its utility in a demonstration project among floor layers.