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51.
Abstract Past research suggests that mail surveys encourage a primacy effect, which is a tendency to choose the first answers from a list, whereas telephone surveys encourage a recency effect, a tendency to choose the last answers from a list. This paper summarizes results from 82 new experiments conducted in 12 separate surveys in seven states. Only four of 33 mail survey comparisons exhibited significant primacy effects, while five of 26 experiments in telephone surveys exhibited recency effects. In addition, only three of 23 cross-method comparisons produced a significant primacy/recency effect in the expected manner. The conclusion is that the prevalence of primacy and recency effects has been over-estimated by past research and a new theoretical approach that takes into account multiple causation is needed for examining these effects.  相似文献   
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53.
Although concerns have frequently been raised recently regarding the quality of life of intercollegiate athletes, information is seldom available on which college and university administrators can base policy decisions. Particularly lacking are studies that provide administrators with assessments of their own athletics programs relative to athletics programs at other institutions. We describe here a method we used in conducting a comparative evaluation of the status of student-athletes at a large public university, involving comparisons of student-athletes at this university to student-athletes at a subset of the institutions that participated in the 1987–88 National Study of Intercollegiate Athletes. By utilizing existing data sets to construct comparison samples, relative assessments of the status of student-athletes at a given institution can be performed without the excessive costs of gathering data on student-athletes at comparison institutions. Techniques employed in data collection and analysis are discussed as well as the format of the report in which the findings of the study were presented.  相似文献   
54.
Debates about regulatory efforts to monitor the delivery of health and long-term care have become commonplace in health policy. Efforts to examine the key assumptions underlying the current regulatory strategies have been limited, however. Using the board and care industry as an example, this article examines how ideology influences the regulatory strategy developed. Three ideological perspectives-a free-market approach, a market correction strategy, and a critical policy framework-are reviewed in the context of efforts to regulate board and care homes in the United States. Differences in approaches to regulating board and care are presented for each of the major perspectives.  相似文献   
55.
The contemporary retreat from marriage in the United States has had a differential impact across socioeconomic and racial groups. Here, 1990 marriage rates and propensities for Virginia, North Carolina, and Wisconsin are analyzed regarding (a) the likelihood that persons in different groups ever marry and (b) patterns of partner choice with respect to race and educational level. Marriage remains strong in most race‐education groups but is substantially lower among Blacks and among those with less than 12 years of education. Patterns of partner choice have shifted to show greater symmetry between the educational levels of brides and grooms. Changes have been modest with regard to the level and pattern of interracial (Black‐White) marriage. Marriage is increasingly a union of equals, but a union chosen more by Whites than by Blacks and more by the well educated than by the poorly educated.  相似文献   
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57.
Recent studies demonstrating a concentration dependence of elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suggest that previous estimates of exposure for occupationally exposed cohorts may have underestimated actual exposure, resulting in a potential overestimate of the carcinogenic potency of TCDD in humans based on the mortality data for these cohorts. Using a database on U.S. chemical manufacturing workers potentially exposed to TCDD compiled by the National Institute for Occupational Safety and Health (NIOSH), we evaluated the impact of using a concentration- and age-dependent elimination model (CADM) (Aylward et al., 2005) on estimates of serum lipid area under the curve (AUC) for the NIOSH cohort. These data were used previously by Steenland et al. (2001) in combination with a first-order elimination model with an 8.7-year half-life to estimate cumulative serum lipid concentration (equivalent to AUC) for these workers for use in cancer dose-response assessment. Serum lipid TCDD measurements taken in 1988 for a subset of the cohort were combined with the NIOSH job exposure matrix and work histories to estimate dose rates per unit of exposure score. We evaluated the effect of choices in regression model (regression on untransformed vs. ln-transformed data and inclusion of a nonzero regression intercept) as well as the impact of choices of elimination models and parameters on estimated AUCs for the cohort. Central estimates for dose rate parameters derived from the serum-sampled subcohort were applied with the elimination models to time-specific exposure scores for the entire cohort to generate AUC estimates for all cohort members. Use of the CADM resulted in improved model fits to the serum sampling data compared to the first-order models. Dose rates varied by a factor of 50 among different combinations of elimination model, parameter sets, and regression models. Use of a CADM results in increases of up to five-fold in AUC estimates for the more highly exposed members of the cohort compared to estimates obtained using the first-order model with 8.7-year half-life. This degree of variation in the AUC estimates for this cohort would affect substantially the cancer potency estimates derived from the mortality data from this cohort. Such variability and uncertainty in the reconstructed serum lipid AUC estimates for this cohort, depending on elimination model, parameter set, and regression model, have not been described previously and are critical components in evaluating the dose-response data from the occupationally exposed populations.  相似文献   
58.
Planning the gambling environment requires protection of the public's health, safety and welfare. Whereas most public gaming provisions and statutes address the public's fears of organized crime as well as some welfare needs, rarely do they safeguard the public's health regarding the spread of the mental disease known as pathological gambling. Measurement of the prevalence and incidence of this disease would enable policy planners to evaluate both the state's responsibility for an epidemic and the adequacy of publicly funded treatment programs. The purpose of this paper is to examine the methods which underlie three different estimates of the prevalence rate of pathological gambling and to critique them in the light of sound epidemiological procedure. In 1975, the Institute for Social Research (ISR) of the University of Michigan conducted a national survey and a survey of the state of Nevada on behalf of the U.S. Commission on a National Policy Toward Gambling. Using discriminant function analysis coupled with subjective inspection of cases in the at-risk pool, the researchers estimated rates of probable and potential pathological gamblers. In 1984 and 1985, this author surveyed residents in the Delaware Valley and the state of Ohio using the cumulative clinical signs method which also posited rates of probable and potential pathological gamblers. In 1986, researchers at the Office of Mental Health for the State of New York employed a formal screening device to survey residents and proposed a rate of probable pathological gamblers and a rate of problem — although not pathological — gamblers. All three approaches produced different estimates. The utility of prevalence and incidence rate research in this field is threatened by a lack of consensus about the proper epidemiological procedure to be employed in arriving at these estimates. There is also confusion about the distinction between a probable and a potential pathological gambler. The planning purpose, method, validity and reliability of prevalence rate research about pathological gambling are addressed in this paper.  相似文献   
59.
Principal curves revisited   总被引:15,自引:0,他引:15  
A principal curve (Hastie and Stuetzle, 1989) is a smooth curve passing through the middle of a distribution or data cloud, and is a generalization of linear principal components. We give an alternative definition of a principal curve, based on a mixture model. Estimation is carried out through an EM algorithm. Some comparisons are made to the Hastie-Stuetzle definition.  相似文献   
60.
Book reviews     
Nathan Glazer Ethnic Dilemmas Harvard, Harvard University Press. 1985

Giddens, Anthony The Constitution of Society, Berkeley, University of California, 1985, pp.XXXVII, 402. Notes, glossary, diagrams, bibliographic notes and index.

Jeremy Rifkin Declaration of a Heretic. Boston. London, Melbourne and Henley, Routledge and Kegan Paul, 1985, pp.X,140.

Ted Benton The Rise and Fall of Structural Marxism: Althusser and his Influence, New York, St.Martin's Press, 1984, pp. VII,259.

Raymond L. Garthoff Détente and Confrontation Washington, The Brookings Institution, 1985, pp.XVI,1126.

Joseph J. Collins The Soviet Invasion of Afghanistan. A Study in the Use of Force in Soviet Foreign Policy, Massachusetts/Toronto, D.C. Heath and Company/Lexington, 1986, pp. XV, 195.

Jan Shipps Mormonism: The Story of a New Religious Tradition, Chicago, University of Illinois Press, 1985, pp.211.

Robert Jay Lifton Home from the War: Vietnam Veterans: Neither Victims nor Executioners, New York, Basic Books, 1985, pp.478  相似文献   

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