A distribution-free approach to qdantal response assays

A nonparametric method is developed to estimate the minimum dosage level required to induce a given response rate in an experiment. The only assumption used about the response rate is that it is a nondecreasing function with respect to the dosage level. Let n_isubjects be independently tested at dosage level x_ix₁x₂x_k. This paper presents methodology for the estimation of the smallest i such that the response probability at x_i is no less than a required level p. A comparison with well-known nonparametric methods shows that this method is better in some cases. A design of minimum required sample size for a given accuracy is also developed.     

A COMPARISON OF FAMILY ADAPTATIONS TO HAVING A CHILD WITH CYSTIC FIBROSIS

The effect of Cystic Fibrosis (CF) on the structure and social climate of the family was examined with self-report scales and independent observations of family functioning. Families in which the child with CF was not the firstborn were found to be functioning more healthily than those in which the child was the firstborn. This was found on 7 of 10 family environment scales, a family hierarchy test, and on all three of the family system scales used by the independent observers (power, cohesion and closeness). Significant correlations between specific family variables and problem behaviors and social competencies were also found.     

Perceived Risk, Stigma, and Potential Economic Impacts of a High-Level Nuclear Waste Repository in Nevada

This study investigates the potential impacts of the proposed nuclear waste repository at Yucca Mountain, Nevada, upon tourism, retirement and job-related migration, and business development in Las Vegas and the state. Adverse impacts may be expected to result from perceptions of risk, stigmatization, and socially amplified reactions to "unfortunate events" associated with the repository (major and minor accidents, discoveries of radiation releases, evidence of mismanagement, attempts to sabotage or disrupt the facility, etc.). The conceptual underpinnings of risk perception, stigmatization, and social amplification are discussed and empirical data are presented to demonstrate how nuclear images associated with Las Vegas and the State of Nevada might trigger adverse economic effects. The possibility that intense negative imagery associated with the repository may cause significant harm to Nevada's economy can no longer be ignored by serious attempts to assess the risks and impacts of this unique facility. The behavioral processes described here appear relevant as well to the social impact assessment of any proposed facility that produces, uses, transports, or disposes of hazardous materials.     

“Just a hunch”: Accuracy and awareness in person perception

Person perception tasks involving nonverbal communication have a mystified reputation. It is frequently argued that nonverbal cues are accurately, but only unconsciously, perceived. This may explain the frequent response of judges who, when asked to decode a sample of nonverbal behavior, reply that it was just a hunch—i.e., show little or no awareness of how they arrived at a judgment, even a correct one. Two alternative models, the Unconsciousness hypothesis and the Inarticulation hypothesis are posited to describe the possible relationship between accuracy and awareness. Two studies are reported on the relationship between accuracy and awareness, both using the Interpersonal Perception Task (IPT). In the first study, the IPT was given to a sample of 476 undergraduates. Accuracy was measured by how many of the 30 IPT questions these judges answered correctly. Global awareness was indexed by having each judge guess how many of the 30 scenes they had answered correctly. In this coarse analysis, the accuracy-awareness relationship was positive but weak. A second experiment was conducted to produce more fine-grained tests of the accuracy-awareness relationship. Different versions of the IPT were presented to 134 undergraduates. Judges given each version of the IPT were asked to indicate their degree of confidence in each one of their answers. This second experiment found a positive, substantial relationship between accuracy and awareness, and this relationship was particularly strong when analyzed across experimental conditions as a whole. These findings support the Inarticulation hypothesis, and cast doubt on the Unconsciousness hypothesis. Implications for an emerging understanding of how nonverbal communication is processed are discussed.We wish to thank Robin Akert and Bob Rosenthal for helpful advice and inspiration.     

Enforcing shape constraints on a probability density estimate using an additive adjustment curve

A method is proposed for shape-constrained density estimation under a variety of constraints, including but not limited to unimodality, monotonicity, symmetry, and constraints on the number of inflection points of the density or its derivative. The method involves computing an adjustment curve that is used to bring a pre-existing pilot estimate into conformance with the specified shape restrictions. The pilot estimate may be obtained using any preferred estimator, and the optimal adjustment can be computed using fast, readily-available quadratic programming routines. This makes the proposed procedure generic and easy to implement.     

Size distributions reconsidered

We consider tests of the hypothesis that the tail of size distributions decays faster than any power function. These are based on a single parameter that emerges from the Fisher–Tippett limit theorem, and discriminate between leading laws considered in the literature without requiring fully parametric models/specifications. We study the proposed tests taking into account the higher order regular variation of the size distribution that can lead to catastrophic distortions. The theoretical bias corrections realign successfully nominal and empirical test behavior, and inform a sensitivity analysis for practical work. The methods are used in an examination of the size distribution of cities and firms.     

The NISO Institutional Identifiers (I2) Working Group

Recognizing the importance of the institution as a critical entity in any information model, from information creation to information sharing, NISO (National Information Standards Organization) has formed a working group to develop a standard (Z39.94) for identifying institutions. This installment of “Standards Update” will discuss the mission and objectives of that working group and provide some information about its timelines for developing the standard.