Assessing Social Isolation: Pilot Testing Different Methods

Social isolation is a significant public health problem among many older adults; however, most of the empirical knowledge about isolation derives from community-based samples. There has been less attention given to isolation in senior housing communities. The objectives of this pilot study were to test two methods to identify socially isolated residents in low-income senior housing and compare findings about the extent of isolation from these two methods. The first method, self-report by residents, included 47 out of 135 residents who completed in-person interviews. To determine self-report isolation, residents completed the Lubben Social Network Scale 6 (LSNS-6). The second method involved a staff member who reported the extent of isolation on all 135 residents via an online survey. Results indicated that 26% of residents who were interviewed were deemed socially isolated by the LSNS-6. Staff members rated 12% of residents as having some or a lot of isolation. In comparing the two methods, staff members rated 2% of interviewed residents as having a lot of isolation. The combination of self-report and staff report could be more informative than just self-report alone, particularly when participation rates are low. However, researchers should be aware of the potential discrepancy between these two methods.     

Tests for properties of residual life

The lOOα -percentile (0 < α < 1) residual life function at time x is defined to be the lOOα -percentile of the remaining life given survival up to time x. Joe and Proschan (1982b) develop tests for testing the alternatives representing decreasing 100α-percentile residual life (DPRL-α ) and the property ‘new better than used with respect to the lOOα -percentile’ (NBUP-α ). In this paper, tests are developed for DPRL[α, l) and NBUP[α, l) alternatives, where DPRL[α, l) is the class of life distributions which are DPRL-β distributions for all a ≤ β < 1 if 0 ≤ α < 1 and for all 0 < β < 1 if α = 0, and NBUP[α, l) is similarly defined. When α = 0, the DPRL[α, l) class of life distributions corresponds to the increasing failure rate class and the NBUP[α, l) class of life distributions corresponds to the new better than used class, and the test statistics are respectively asymptotically equivalent to the Hollander and Proschan (1975) test statistics for decreasing mean residual life and new better than used in expectation alternatives.     

Discrimination indexes and models for studying sensory functioning in aging

A popular paradigm in experimental psychophysics has subjects estimate sensation magnitude by assigning numbers to stimuli in some way. While it is typical to analyze the central tendency (e.g. means and slopes) of the subjects' psychophysical. functions, there is often a greater need to analyze the internal consistency of these functions. A subject who gives increasing mean responses across increasing stimulus intensities and also gives highly consistent responses within stimulus intensities is showing superior sensory discrimination. We propose new discrimination indexes, based on measures of association and lack-of-fit, that summarize monotonic regressions of the subject's data, as well as non-metric and metric-sensitive measures related to Kendall's coefficient of concordance. We use these indexes in quadratic spline regression models for cross-sectional age trends in sensory discrimination, with covariates included to adjust for task demands and gender differences.Because such data are potentially affected by increasing variability with age, we describe a method to assess this and adjust for it using reweighted least squares.     

On Broadening Failure Rate Distributions in PRA Uncertainty Analyses

Several recent nuclear power plant probabilistic risk assessments (PRAs) have utilized broadened Reactor Safety Study (RSS) component failure rate population variability curves to compensate for such things as expert "overvaluation bias" in the estimates upon which the curves are based.
A simple two-components of variation empirical Bayes model is proposed for use in estimating the between-expert variability curve in the presence of such biases. Under certain conditions this curve is a population variability curve. Comparisons are made with the existing method.
The popular procedure appears to be generally much more conservative than the empirical Bayes method in removing such biases. In one case the broadened curve based on the popular method is more than two orders of magnitude broader than the empirical Bayes curve. In another case it is found that the maximum justifiable degree of broadening of the RSS curve is to increase α from 5% to 12%, which is significantly less than the 20% value recommended in the popular approach.     

Humor and hostility: A neglected aspect of social movement analysis

Most research on social movements has focused on their chronology and structure, and on the social conflict generated by collective attempts to bring about or thwart change. The seriousness and intensity of such activity have led sociologists to ignore the lighter side of social movements. Humor is an important means of communication and in this article it is shown to be intimately related to conflict in social movements. A four-cell model of “conflict humor” is proposed. The relationship between humor and social movements is demonstrated in a brief case study of the Western Canadian separatist movement.