Detecting repeated measures effects with univariate and multivariate statistics.

Power differences between multivariate and -adjusted univariate tests are presented for various configurations and sizes of population means, degrees of nonsphericity, and sample sizes for small and large repeated measures designs with 1 within-subjects factor. The results are applicable to various designs (e.g., longitudinal). Power differences were calculated by adapting procedures presented in K. E. Muller and C. N. Barton (1989, 1991). The results demonstrate that, for parametric conditions likely to be encountered by psychological researchers, the differences between the 2 approaches can be considerable. The authors recommend that sample size be chosen according to the procedures enumerated by Muller and Barton but provide simple guidelines for use when the information required by the Muller-Barton approach is not available. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using the 'new' statistics in nursing research

This paper argues that quantitative methods are under-used in nursing research. Although this is often because the qualitative approach is the most appropriate, it may also be because nurse researchers are not fully aware of modern, sophisticated data analysis techniques and have tended to use simple statistical techniques that often make the quantitative analysis of complex data very difficult and produce simplistic and unsatisfactory answers. The paper briefly discusses probability and survival modelling techniques suitable for use in complex nursing research situations and argues that these methods may help to bridge the qualitative-quantitative gap. Although these techniques are mathematically complex, they are easily applied in practice using dedicated computer programs. The paper describes their application using one such program, GLIM 4.     

Comparative assessment of multivariate association in psychological research.

Develops the notion of multivariate association among the variables in a set. Procedures stemming from an earlier inferential test are presented for comparing, between 2 populations, the strength of association that is present simultaneously in all pairs in a set of variables. Results are outlined of an investigation, using computer simulation methods, of the test statistic's sampling properties. The statistic is shown to follow closely the central F distribution, thus permitting adequate control of Type-I error. Applications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Uses of discriminant analysis following MANOVA: Multivariate statistics for multivariate purposes.

When a test of multiple ANOVA is found to be significant, it must be followed by other analyses before a researcher can arrive at an accurate understanding of the data set. Two possibilities for follow-up analyses include univariate ANOVA and discriminant analysis. This article presents the results of a Monte Carlo study (N?=?450) wherein typical, but simple, multivariate data were analyzed by the 2 techniques. Results demonstrate that discriminant analysis is capable of showing the underlying dimensionality of the data as well as determining the contribution of individual variables to the underlying dimensions, whereas ANOVA is limited to specifying the contribution of each variable to group separation. It is argued that when researchers analyze multivariate data, primary goals become interpretation and understanding the data set. It is concluded that discriminant analysis is most suitable for this purpose. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multivariate statistics for family psychology research.

The application of selected multivariate statistics is illustrated for use in family psychology research. The use of multivariate analysis of variance (MANOVA) and discriminant analysis in factorial designs and profile analysis is discussed. Profile analysis provides a method for dealing with unit of analysis issues in family psychology research. Applications of confirmatory factor analysis are also discussed as useful methods for researchers examining multiple components of families and handling multiple perspectives of various family members. Limitations and applications of these methods in family psychology research are reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于多元统计学的大尹格庄金矿床深部地球化学找矿标志研究

在大尹格庄金矿床深部勘查钻孔ZK4孔地球化学测量的基础上,通过应用多元统计学中的相关分析、聚类分析和因子分析,探讨与Au成矿有关的深部地球化学找矿标志。研究结果表明:Hg可做为该矿床与Au成矿有关的通用指示元素;Au和Ag的相关系性最高,Ag可作为矿区内找金的指示元素;因子分析中公因子为典型的热液矿床元素组合;Au-Ag-Bi是该金矿床成矿预测最有效的指示标志。     

试论统计模型在统计认识中的作用

统计工作是社会经济管理中一项重要的工作.传统的统计方法主要是描述性统计,数据资料主要靠统计报表来搜集整理,所得出的结论往往与实际情况有较大差距.本人通过长期讲授<统计学原理>,深感统计模型在统计工作中的重要作用.应用统计模型,可以提高数据资料应用的可靠性和可行性,从而可以对经济现象的发展前景,做量上的预计和推算,对经济决策、计划管理提供重要的参考依据.     

MR spectroscopy in clinical research

MR spectroscopy (MRS) offers unique possibilities for non-invasive evaluation of biochemistry in vivo. During recent years there has been a growing body of evidence from clinical research studies on human beings using 31P and 1H MRS. The results indicate that it is possible to evaluate phosphorous energy metabolism, loss of neurones, and lactate production in a large number of brain diseases. Furthermore, 31P and 1H MRS may be particularly clinically useful in evaluation of various disorders in skeletal muscle. In the heart 31P MRS seems at the moment the most suitable for evaluation of global affections of the myocardium. In the liver 31P MRS appears to be rather insensitive and non-specific, but absolute quantification of metabolite concentrations and using metabolic "stress models" may prove useful in the future. The clinical role of MRS in oncology is still unclear, but it may be useful for non-invasive follow-up of treatment. Taken together, the evidence obtained so far certainly shows some trends for clinical applications of MRS. Methods are now available for the clinical research necessary for establishing routine clinical MRS examinations.     

Current opportunities in clinical research

The dissolution rates and bioavailability of norfloxacin in seven batches of norfloxacin capsules produced by five pharmaceutical factories were studied with rotating basket and UV-spectrophotometry. The results showed that the T50, Td and m of the samples had obvious differences, and the correlation between the dissolution rate and bioavailability differed very obviously. The method used is simple and convenient. So UV-spectrophotometry is one of the methods for the assay of norfloxacin preparations in vitro and in vivo.     

Professional integrity in clinical research

In response to public concern over abuses in human medical experimentation, the dominant approach to the ethics of clinical research during the past 30 years has been regulation, particularly via institutional review board review and approval of scientific protocols and written consent forms. However, the effectiveness of regulatory mechanisms in ensuring the ethical conduct of clinical research is limited. Little attention has been devoted to the nature and role of professional integrity of physician investigators, a conscientious framework for guiding investigators in the socially important but morally complex activity of clinical research. Professional integrity is vital in forging an ethically sound relationship between investigators and patient volunteers, a relationship that differs in important ways from the patient-physician relationship in standard clinical practice. We examine critically 2 models of the moral identity of physician investigators, the investigator as clinician and the investigator as scientist; in neither of these 2 models can the physician investigator eliminate completely the moral conflicts posed by clinical research. The professional integrity of physician investigators depends on a coherent moral identity that is proper to the enterprise of clinical research. The roles of clinician and scientist must be integrated to manage conscientiously the ethical complexity, ambiguity, and tensions between the potentially competing loyalties of science and care of volunteer patients.     

Ethics and research: ethical considerations in clinical research

Two subjects are discussed: the use of placebo controls in clinical trials and informed consent. Particularly in trials of drugs for disorders for which there exist effective treatments, the use of placebo is still controversial, although anyhow in violation of the Declaration of Helsinki. Informed consent aims at giving a subject all the necessary information to allow him to decide, with full knowledge, whether to accept a particular treatment or experimental protocol. Its importance would seem, albeit essential, to be rather illusory.     

Type I error in counseling research: A plea for multivariate analyses.

Maintains that a Type I error becomes inflated beyond conventional acceptable levels when a researcher performs individual univariate statistics (such as t tests or ANOVAs) on each of several dependent variables within a single research project. The present article examines the prevalence of inflated Type I error in counseling research and recommends wider use of multivariate statistics to correct the problem. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The continuity principle in psychological research: An introduction to robust statistics.

Examines the importance of robust statistics in psychological research and suggests that the classical estimates of means, variances, and correlations are sensitive to small departures from the normal curve. Statisticians have urged caution in the use of classical statistics and have proposed a variety of alternatives that are robust with respect to departures from normality. Common sources of nonnormality in psychological data cleaning and robust estimation are examined. Robust estimation using M-estimators is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)