Airline Safety Improvement Through Experience with Near‐Misses: A Cautionary Tale

In recent years, the U.S. commercial airline industry has achieved unprecedented levels of safety, with the statistical risk associated with U.S. commercial aviation falling to 0.003 fatalities per 100 million passengers. But decades of research on organizational learning show that success often breeds complacency and failure inspires improvement. With accidents as rare events, can the airline industry continue safety advancements? This question is complicated by the complex system in which the industry operates where chance combinations of multiple factors contribute to what are largely probabilistic (rather than deterministic) outcomes. Thus, some apparent successes are realized because of good fortune rather than good processes, and this research intends to bring attention to these events, the near‐misses. The processes that create these near‐misses could pose a threat if multiple contributing factors combine in adverse ways without the intervention of good fortune. Yet, near‐misses (if recognized as such) can, theoretically, offer a mechanism for continuing safety improvements, above and beyond learning gleaned from observable failure. We test whether or not this learning is apparent in the airline industry. Using data from 1990 to 2007, fixed effects Poisson regressions show that airlines learn from accidents (their own and others), and from one category of near‐misses—those where the possible dangers are salient. Unfortunately, airlines do not improve following near‐miss incidents when the focal event has no clear warnings of significant danger. Therefore, while airlines need to and can learn from certain near‐misses, we conclude with recommendations for improving airline learning from all near‐misses.     

For what use are tests of hypotheses and tests of significance

Tests of sharp null hypotheses, although frequently computed, are.rarely appropriate as the major end product of statistical analyses, except possibly in some, areas of the natural sciences. But procedures closely akin to tests, although often less formal, are needed in almost every investigation in which exploratory data analysis is used to help to decide upon the statistical model appropriate for the final analysis. The term “diagnostic check”has been suggested by Box and Jenkins for these procedures. Traditional statistical tests often suggest useful diagnostic checks -and this, in my view, is what tests are mainly good for-but visual examination and interpretation of data plots are often equally important. Biere is also much to be gained by the development of new diagnostic checks, and testing theory may be useful as one guide to this development.     

One sided acceptance sampling by variables: the case of the laplace distribution

The theory of acceptance sampling by variables is well known when the underlying distribution is normal. When the normality assumption is not true, using the usual normal case method can be quite misleading. In this paper we deal with the Laplace distribution for both the standard deviation known and then unknown. We establish a decision rule for accepting a lot of product containing a defective proportion p. We determine the density function of the decision rule statistic, for small and large sample sizes. We give some practical ways to choose the sample size and the acceptance constant to obtain a desired operating characteristic curve     

Peak performing organisations

The literature on organisational performance is riddled with measurement problems that cannot easily be solved. In contrast we argue that elite theory in terms of performance can be more easily measured by the win record of sports organisations. Accordingly, this article argues that certain organisational peak practices are key to understanding how peak performance is sustained. Through data collected from the top ten sports organisations in the world we introduce the embryonic theory of Peak Performing Organisations (PPO). Sustained PPO practices offer more robust outcomes than the genre of High Performing Organisations.     

State Responses to Alcohol Use and Pregnancy: Findings From the Alcohol Policy Information System

This article describes U.S. state policies related to alcohol use during pregnancy, using data from the National Institute on Alcohol Abuse and Alcoholism Alcohol Policy Information System. Specifically, this study examines trends in policies enacted by states over time and types of policies enacted across states in the United States, with a focus on whether laws were supportive or punitive toward women. Findings revealed substantial variability in characteristics of policies (19 primarily supportive, 12 primarily punitive, 12 with a mixed approach, and 8 with no policies). Findings underscore the need to examine possible consequences of policies, especially of punitive policies and “mixed” approaches.     

Reverse Regression,Fairness, and Employment Discrimination

Possible salary discrimination can be studied by comparing mean salaries of, say, males and females, after statistical adjustment for differences in job qualifications. The adjustment is often made by regression, with salary as dependent variable, and job qualifications and sex as independent variables. One might also regress job qualifications on salary and sex, a procedure called reverse regression. Ideas about fairness as well as technical concepts are relevant to discrimination studies. There are two distinct aspects of fairness, one based on comparisons of salary and the other based on comparisons of qualifications. Both concepts are needed to evaluate fairness.     

Feasibility of a Telephone Follow-Up on Use of Emergency Contraceptive Pills in a College Health Center

Abstract

The authors examined the feasibility and effectiveness of a telephone follow-up procedure on use of emergency contraceptive pills (ECP) at a college health center. They made 264 telephone calls to the 97 women who had received ECPs during one 16-week academic semester and were successful in reaching 65 (67%) of the women, who responded with information about their experiences with ECPs. The women demonstrated a high rate of adherence to the medical regimen and reported very few side effects from ECPs; a majority said that ECPs did not affect their ability to carry out daily activities. On weighing the relative absence of problems following ECP distribution against the time, effort, and cost required to reach just over two thirds of the women, the researchers concluded that an ECP telephone follow-up procedure was neither cost-effective nor particularly useful.     

Training Police Social Workers: A Neglected Area of Social Work Education

This article begins with a discussion of the vital need for collaboration between social work and law enforcement professionals, with particular emphasis on the need for comprehensive training programs combining criminal justice and social work knowledge. It then documents several historical recommendations for training police social workers that are relevant today, and suggests that social work education programs of the future include provisions for transmitting social work knowledge to police officers. Similarly, social workers planning to practice in criminal justice settings need to have training in the administration of justice.