DELIBERATELY BIASING SURVEY QUESTIONS

In “before” and “after” surveys of Attitudes Towards Random Breath Testing in South Australia, three basic versions of the questionnaire were used. In the first, a set of “lead-up” questions, which were designed to deliberately bias the results towards acceptance of the tests, was included before the main questions; in the second, there were no lead-up questions; in the third, a different set of lead-up questions was used, and was aimed at deliberately biasing the results against the tests. The results in two out of the four attempts to influence the answers (compared with no lead-up questions) were significant in the expected direction, and in the other two cases were in the correct direction but not significant. The difference between the positive-and negative-biasing versions was highly significant in both cases. It is important to be aware that changes in context rather than in question wording per se can give rise to effects which dwarf the sampling error.     

Perspectives on antenatal education associated with pregnancy outcomes: Systematic review and meta-analysis

BackgroundMany studies on the relation between maternal health and infant health, including the effect of structured antenatal education, have been published and expanded over the years.AimInvestigate the impact of various antenatal education programmes on pregnancy outcomes to aid the development of future guidelines related to maternal and foetal health.MethodsBibliographic databases (Cochrane, PubMed, EMBASE, CINAHL, Korean Studies Information Service System) were searched up to November 2018, following the PICO criteria: population (pregnant women), intervention (antenatal education), comparison (not specified), and outcome (maternal and foetal outcome including physical or mental health components).FindingsWe included 23 eligible studies consisting of 14 controlled trials and 9 observational studies. The maternal physical outcomes depending on participation in antenatal education were not significantly different; however, the caesarean birth rate was lower in the antenatal education group (relative risk, RR, 0.90; 95% confidence interval, CI, 0.82–0.99), as was the use of epidural anaesthesia (RR, 0.84; 95% CI, 0.74–0.96). The maternal mental health outcomes of stress and self-efficacy significantly improved in the antenatal education group, although there was no difference in anxiety and depression. The foetal outcomes of birth weight or gestational age at birth were also not different between the groups.ConclusionAntenatal education can reduce maternal stress, improve self-efficacy, lower the caesarean birth rate, and decrease the use of epidural anaesthesia; however, there is limited evidence of its effects on maternal or foetal physical outcomes. Therefore, antenatal education should be standardised to elucidate its actual mental and physical health effects.     

试论无效行政行为——兼论我国无效行政行为的制度构建

无效行政行为是从大陆法系国家引入的具有特定涵义的概念,其存在的理论基础是行政法治原则、行政抵抗权和有限公定力原理.无效行政行为的判断标准有一般标准和具体标准.我国应完善无效行政行为的制度设计.     

康德《判断力批判》中的自然美与艺术美

康德在其哲学体系中将判断力作为知性与理性的桥梁,《判断力批判》两大部分审美判断力批判与目的论判断力批判不可分割为这一主旨服务。而康德对自然美与艺术美的分析则体现了他对道德律令以及人作为最终目的的重视。在美的艺术中,康德力图将天才与鉴赏,自然美与艺术美进行统一与融合。     

Local and Variable Bandwidths and Local Linear Regression

Two types of non-global bandwidth, which may be called local and variable, have been defined in attempts to improve the performance of kernel density estimators. In nonparametric regression, local linear fitting has become a method of much popularity. It is natural, therefore, to consider the use of non-global bandwidths in the local linear context, and indeed local bandwidths are often used. In this paper, it is observed that a natural proposal in the literature for combining variable bandwidths with local linear fitting fails in the sense that the resulting mean squared error properties are those normally associated with local rather than variable bandwidths. We are able to understand why this happens in terms of weightings that are involved. We also attempt to investigate how the bias reduction expected of well-chosen variable bandwidths might be achieved in conjunction with local linear fitting.     

Some Remarks about Robust Estimation of the Scale Parameter in Weighted Models

Using Zieliński's (1977 Zieliński , R. ( 1977 ). Robustness: a quantitative approach . Bull. Acad. Polon. Sci., Ser. Sci. Math. Astronom. Phys. 25 : 1281 – 1286 . [Google Scholar]) concept of robustness, B?a?ej (2007 B?a?ej , P. ( 2007 ). Robust estimation of the scale and weighted distributions . Appl. Math. (Warsaw) 34 : 39 – 45 . [Google Scholar]) obtained the uniformly most bias-robust estimates (UMBREs) of the scale parameter for some statistical models, in a class of linear functions of order statistics. Violations of the models are generated by weight functions. In this article the UMBRE of the scale parameter, based on order statistics, a more general weighted model is derived. Extension of a result of B?a?ej (2007 B?a?ej , P. ( 2007 ). Robust estimation of the scale and weighted distributions . Appl. Math. (Warsaw) 34 : 39 – 45 . [Google Scholar]) is given.     

Some Classes of Estimators for Median Estimation in Survey Sampling

In this article, we have suggested some classes of estimators for estimating finite population median using information on an auxiliary variable. To study the properties of suggested classes of estimators under large sample approximation, a generalized class of estimators has been suggested with its properties. It has been shown that the suggested classes of estimators are more efficient than other existing estimators. The results have been illustrated through an empirical study.     

An Improved Class of Estimators for the General Population Parameters Using Auxiliary Information

This article suggests an improved class of estimators for estimating the general population parameter using information on an auxiliary variable. The properties of the suggested class of estimators have been studied under large sample approximation. The general results are then applied to estimate the population coefficient of variation of study variable using auxiliary information. An empirical study is given in support of the theoretical results.     

Bias-corrected maximum likelihood estimation of the parameters of the generalized Pareto distribution

ABSTRACT

We derive analytic expressions for the biases, to O(n^?1), of the maximum likelihood estimators of the parameters of the generalized Pareto distribution. Using these expressions to bias-correct the estimators in a selective manner is found to be extremely effective in terms of bias reduction, and can also result in a small reduction in relative mean squared error (MSE). In terms of remaining relative bias, the analytic bias-corrected estimators are somewhat less effective than their counterparts obtained by using a parametric bootstrap bias correction. However, the analytic correction out-performs the bootstrap correction in terms of remaining %MSE. It also performs credibly relative to other recently proposed estimators for this distribution. Taking into account the relative computational costs, this leads us to recommend the selective use of the analytic bias adjustment for most practical situations.     

Comparison of the bias of trimmed and Winsorized means

ABSTRACT

We derive sharp upper and lower projection bounds on the bias of two-sided Winsorized means. To determine the projection of appropriate function, we consider new analytic condition which describes the form of the corresponding greatest convex minorant. Then we compare numerically obtained bounds for trimmed and Winsorized means. We conclude that if we have no information about the underlying distribution then Winsorized means are better than the trimmed ones.