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801.
Consider comparing between two treatments a response variable, whose expectation depends on the value of a continuous covariate in some nonlinear fashion. We fit separate segmented linear models to each treatment to approximate the nonlinear relationship. For this setting, we provide a simultaneous confidence band for the difference between treatments of the expected value functions. The treatments are said to differ significantly on intervals of the covariate where the simultaneous confidence band does not contain zero. We consider segmented linear models where the locations of the changepoints are both known and unknown. The band is obtained from asymptotic results. 相似文献
802.
803.
Shih-Ming Hu Cheng-I Wei Margaret R. Schlais Jung-Mao Yeh 《Journal of Housing for the Elderly》2013,27(1-2):45-65
ABSTRACT The purpose of this study is to evaluate the potential of college towns as retirement communities. The uniqueness of college towns as potential retirement communities are identified and discussed. Differences between college towns and Sunbelt state retirement destinations regarding the factors that are most concerned by retiree migrants in their decision-making for relocation were compared. The results showed no differences between the college towns and the Sunbelt state retirement cities. Only a few differences existed among the college town subgroups. The findings are of value to the senior living industry, local government and chamber of commerce in their efforts in marketing college towns as prospective retirement communities. 相似文献
804.
António J. Santos Inês Peceguina João R. Daniel Nana Shin Brian E. Vaughn 《Social Development》2013,22(1):163-179
This study tested assumptions and conclusions reached in an earlier confirmatory factor analysis (CFA) study of the social competence (SC) construct for preschool children. Two samples (total N = 408; a new Portuguese sample and one from US samples that had participated in the original study) contributed data. Seven SC indicators were tested for mean differences across age, sex, and sample. Significant sex differences were found for peer acceptance (favoring girls) and for initiating affectively neutral interactions (boys had higher rates), and the sex by sample interaction also was significant for initiating interactions (i.e., effect significant only in the Portuguese sample). In CFAs, the hypothesized structure of SC fits the data and was invariant across sample and age within sample in both measurement and structural tests. The model was invariant at the measurement level for sex within sample tests, but not at the structural level. The results replicate and extend understandings of SC reported in the original study. 相似文献
805.
Peter E. L. Marks Ben Babcock Antonius H. N. Cillessen Nicki R. Crick 《Social Development》2013,22(3):609-622
Although low participation rates have historically been considered problematic in peer nomination research, some researchers have recently argued that small proportions of participants can, in fact, provide adequate sociometric data. The current study used a classical measurement perspective to investigate the internal reliability (Cronbach's α) of peer nomination measures of acceptance, popularity, friendship, prosocial behavior, and overt aggression. Data from 642 participants attending 10 schools were resampled at different participation rates ranging from 5 percent to 100 percent of the original samples. Results indicated that (1) the association between participation rate and Cronbach's α was curvilinear across schools and variables; (2) collecting more data for a given variable (by using unlimited vs. limited nominations, or two vs. one items) was significantly related to higher internal reliability; and (3) certain variables (overt aggression, popularity) were more reliable than others (acceptance, friendship). Implications for future research were discussed. 相似文献
806.
D. M. R. Sekhar 《Accountability in research》2013,20(5):257-263
Publication of scientific research in print is traditionally peer reviewed anonymously prior to publication, which is a time-tested process but has serious limitations. The advent of the Internet permits postpublication open review online after minimal review by the editors or the author-selected reviewers, which can be quick, that permits the authors to revise the content. Most meritorious articles published online may be selected for publication in print as annual or biennial collections. 相似文献
807.
A simple adaptation of a distribution-free method due to Scholz (1978) and Sievers (1978) for inference in a single regression setting is proposed for inference about the difference in slopes of two regression lines. We assume that the data are obtained from a designed experiment with common regression constants. A comparison of the proposed method to its competitors-one due to Hollander and the other due to Rao and Gore-indicates superiority of the new method. 相似文献
808.
Traditionally, the moments of the Weibull distribution have been calculated using the standard Weibull (Johnson and Kotz, 1970) . This article will expand on that idea and cover the truncated cases for the standard Weibull distributions. Also, the same techniques used for the standard form will be used to derive the moment expressions for the three-parameter complete and truncated Weibull distributions. The summary statistics are then calculated from the moment expressions. Weibull moments involve the gamma and incomplete gamma functions. 相似文献
809.
We consider the problem of UMVU estimation of a U-estimable function of four unknown truncation parameters based on two independent random samples from two two-truncation parameter families. In particular, we obtain the UMVU estimator of functional, P (Y > X). Also the confidence intervals for some parametric functions are obtained. 相似文献
810.
Most models for incomplete data are formulated within the selection model framework. Pattern-mixture models are increasingly seen as a viable alternative, both from an interpretational as well as from a computational point of view (Little 1993, Hogan and Laird 1997, Ekholm and Skinner 1998). Whereas most applications are either for continuous normally distributed data or for simplified categorical settings such as contingency tables, we show how a multivariate odds ratio model (Molenberghs and Lesaffre 1994, 1998) can be used to fit pattern-mixture models to repeated binary outcomes with continuous covariates. Apart from point estimation, useful methods for interval estimation are presented and data from a clinical study are analyzed to illustrate the methods. 相似文献