Single-pass low-storage arbitrary quantile estimation for massive datasets

We present a single-pass, low-storage, sequential method for estimating an arbitrary quantile of an unknown distribution. The proposed method performs very well when compared to existing methods for estimating the median as well as arbitrary quantiles for a wide range of densities. In addition to explaining the method and presenting the results of the simulation study, we discuss intuition behind the method and demonstrate empirically, for certain densities, that the proposed estimator converges to the sample quantile.     

A life satisfaction measure: Additional validational data for the Congruity Life Satisfaction measure

Meadowet al. (1992) have developed a measure of life satisfaction based on judgment theory, referred to as Congruity Life Satisfaction (CLS). This paper reports the results of a major study involving six samples from different countries testing the construct validity of the CLS measure. The results of these studies provide additional validational support for the CLS measure.     

Exposure Assessment: Methods of Analysis for Environmental Carcinogens1

Human populations are exposed to environmental carcinogens in both indoor and outdoor atmospheres. Recent studies indicate that pollutant concentrations are generally higher in indoor atmospheres than in outdoor. Environmental pollutants that occur in indoor air from a variety of sources include radon, asbestos, organic and inorganic compounds, and certain particles (e.g., tobacco smoke). Some of the gases or vapors are adsorbed on suspended particulate matter, whereas others exist entirely in the gas phase or are distributed between the latter and a particle-bound state. Because of differences in chemical and physical properties, each class of carcinogens generally requires different sampling and analytical methods. In addition, a single indoor environment may contain a wide variety of air pollutants from different sources. Unfortunately, no single best approach currently exists for the quantitative determination of such complex mixtures and, for practical reasons, only the more toxic or the more abundant pollutants are usually measured. This paper summarizes the currently available monitoring methods for selected environmental pollutants found in indoor atmospheres. In addition, some possible sources for those pollutants are identified.     

A theoretically derived model of premarital intervention: The building of a family system

Premarital intervention programs are on the rise in the United States despite the absence of persuasive empirical data that substantiate their effectiveness. In addition to this lack of strong empirical support, many premarital counseling programs fail to articulate any coherent theory of family process or family intervention which serve as conceptual guideposts for formulating program goals and devising program activities. In this article, the authors describe an experimental program that is conceptually grounded in theories of family process and family intervention. The theoretical rationale for each element included in the program is discussed and numerous examples of the program's content and exercises are offered. Finally, the authors discuss a number of issues central to the evaluation of premarital counseling programs.     

The Causal Sequence of Risk Communication in the Parkfield Earthquake Prediction Experiment

A model of public perception and response to communication about natural hazards risk was constructed. It was estimated on data from samples of households in three communities at risk in the Parkfield earthquake prediction experiment. Estimated model parameters revealed consistent conclusions. Communicated risk information that was reinforced through additional communications and/or social cues precipitated an interactive personal search for more information; personal definitions of risk and what to do emerged; and these social constructions directed how the public responded. Perceived risk only indirectly impacted public action through information searching. This suggests that searching behavior should intervene between perception of risk and response in the theory of public risk communication.     

A Test of the Emergent Norm Theory of Collective Behavior

Objective: The paper uses the timing of evacuation behavior of occupants of the World Trade Center at the time of the explosion of February 26, 1993, to test predictions from Emergent Norm Theory. Method: It uses ordinary least square multiple regression analysis to examine data from a survey done in the first week in May 1993 of 415 people who worked at the World Trade Center. Results: The theory's predictions regarding the additive effects of size of group and preexisting social relationships on the timing of evacuation are supported. However, the findings document important and unexpected interaction effects of these two variables on the effects of perceived threat, resources, and cooperativeness on the timing of evacuation. Conclusion: The results augment the theory by showing the continued importance of enduring social relationships as determinants of collective behavior. Enduring social relationships are not only useful to differentiate collective behavior from institutionalized behavior but also specify the dynamics attending the occurrence of collective behavior.