An Approximation for the Rank Adjacency Statistic for Spatial Clustering with Sparse Data

The rank adjacency statistic D provides a simple method to assess regional clustering. It is defined as the weighted average absolute difference in ranks of the data, taken over all possible pairs of adjacent regions. In this paper the usual normal approximation to the D statistic is found to give inaccurate results if the data are sparse and some regions have tied ranks. Adjusted formulae for the moments of D that allow for the existence of ties are derived. An example of analyses of sparse mortality data (with many regions having no deaths, and hence tied ranks) showed satisfactory agreement between the adjusted formulae and the empirical distribution of the D statistic. We conclude that the D statistic, when used with adjusted moments, provides a valid approximate method to evaluate spatial clustering, even in sparse data situations.     

Water and Salt (I): Yājñavalkya's Saindhava Drstānta (BĀU II 4,12)

Indo-Iranian Journal -     

The Reporting of International News in Canada: Continuity and Change, 1988–2006

This article examines Canadian daily newspaper editors' views regarding the status of international news reporting in Canada. It is based on a series of surveys administered in 1988, 1995, 2000, and 2006 that measured editors' assessments of issues such as the quantity and quality of international news in their papers, the importance they attach to international news coverage, the areas of the world they consider important to cover, and the sources they use for international news. The article uses the data from the surveys to determine whether 11 September 2001 affected editors' perceptions of international news reporting. This question has been widely studied in the United States, but less so in Canada. The central conclusion here is that 9/11 has had only a limited impact on editors' perceptions. The data across all four surveys demonstrate a remarkable degree of consistency in editors' assessments of international news reporting in Canada.