Observations on regression analysis of travel distance on airline distance
In the modeling of urban areas airline distance is often used as a proxy for travel time or distance. This practice has been justified by a high coefficient of determination (R2) between these variables in a random sample of pairs of traffic zones. The ratio of travel distance to airline distance has been used as a measure of network efficiency and called the route factor. This exercise uses hypothetical examples to examine network structure, congestion, and trip production as determinants of route factors and of R2 values of travel distance regressed on airline distance.
The Lowry Model Heritage
Abstract The Lowry model constituted a breakthrough of a particularly intractable conceptual barrier. Notwithstanding its attractive features, including the promise of meaningful operationality, the model has been implemented in only a few domestic applications; its adapters abroad have had more success. In this process, the model has gradually been transformed to more satisfactorily meet the requirements of the regional and transportation planning agencies that depend on allocation modeling. As newly developing conceptual embellishments are made operational, the Lowry model should become an instrument that will enlarge our knowledge of the metropolis and lay a solid foundation for the next generation of models.
Data Driven Policy: The Case for Certification Research
This article describes the program of research being implemented to investigate the outcomes of certification in the U.S. and Canadian workforce and its relevance to the goal of providing policy makers with pragmatic, action-oriented recommendations. Such recommendations encompass policy issues of workforce production, regulation, distribution, financing, and oversight of credentialing organizations. Few studies exist to substantiate the association between certification credentialing and practice outcomes, thereby leaving policy makers, consumers, and nurses in a vacuum when pushed to protect the public through the credentialing vehicles. The Nursing Credentialing Research Coalition (NCRC) has embarked on a research program that will reveal the relationship between certification and its influence on a nurse’s personal, professional, and practice characteristics as well as those judged by consumers and employers. Selected findings and implications for policy are described. Certified nurses’ reports of early interventions for complications are important quality measures for policy.