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Theoretical Validity (theoretical + validity)
Selected AbstractsThe use of conjoint analysis to elicit community preferences in public health research: a case study of hospital services in South AustraliaAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 1 2000Stephen Jan Aims: To demonstrate the use of conjoint analysis (CA) in public health research through a survey of the South Australian community about aspects of their public hospital services. Methods: A series of focus groups determined the most important attributes in choice of hospital services. These were built into a CA survey, using the discrete choice approach. The survey was posted to a representative sample of 700 South Australians. Theoretical validity, internal consistency and non-response bias were all investigated. Results: Some 231 individuals returned the questionnaire. The attribute, ,improvement in complication rates' was positively associated with choice of hospital. Three attributes were found to be negatively associated with such choice: ,waiting times for casualty', ,waiting times for elective surgery' and, anomalously, ,parking and transport facilities'. Travel time' and the cost attribute, ,Medicare levy' were not statistically significant. Trade-offs between the significant attributes were estimated, as were satisfaction or utility scores for different ways of providing hospital services. Results concerning internal consistency and internal validity were encouraging, but some potential for non-response bias was detected. Conclusion: A high premium is placed on the quality of hospital care and members of the community are prepared to choose between hospitals largely on the basis of outcomes and length of waiting times for elective surgery and in casualty. Implications: CA can yield potentially policy-relevant information about community preferences for health services. [source] Theoretical studies on empirical structure,reactivity relationship: the Yukawa,Tsuno equationJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 6 2003Kazuhide Nakata Abstract The substituent-dependent stabilization energies (,X,E) of a series of ,,,-R1R2 benzyl cations were determined by means of ab initio calculation at the MP2/6,31G*//RHF/6,31G*,+,ZPE (scaled 0.8929) level, based on the isodesmic hydride transfer reactions between ring X-substituted and unsubstituted R1R2 benzyl cations. Substituent stabilities (,X,E) of ,,,-dimethylbenzyl cations were determined in the same way, to define a reference set of the ab initio ,+ values. The (,X,E) of ,,,-dimethylbenzyl cations of which the cation center is set orthogonal to the benzene ,-system were correlated linearly with ,0 (solution). Based on this correlation, a set of ab initio ,0 constants [(,0)ab] was determined. The ab initio resonance substituent constants were defined as (,+)ab,,,(,0)ab. Employing the present ab initio set of (,0)ab and constants, the ab initio Yukawa,Tsuno (Y,T) equation was applied to 18 sets of cation stabilities ,X,E associated with hydride transfer reaction systems. Successful applications of the ab initio Y,T equation confirm the theoretical validity of the empirical Y,T relationship; in practice, the Y,T equation makes it possible to divide the electronic substituent effect into the non-resonance and resonance contributions. Copyright © 2003 John Wiley & Sons, Ltd. [source] A self-normalized approach to confidence interval construction in time seriesJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES B (STATISTICAL METHODOLOGY), Issue 3 2010Xiaofeng Shao Summary., We propose a new method to construct confidence intervals for quantities that are associated with a stationary time series, which avoids direct estimation of the asymptotic variances. Unlike the existing tuning-parameter-dependent approaches, our method has the attractive convenience of being free of any user-chosen number or smoothing parameter. The interval is constructed on the basis of an asymptotically distribution-free self-normalized statistic, in which the normalizing matrix is computed by using recursive estimates. Under mild conditions, we establish the theoretical validity of our method for a broad class of statistics that are functionals of the empirical distribution of fixed or growing dimension. From a practical point of view, our method is conceptually simple, easy to implement and can be readily used by the practitioner. Monte Carlo simulations are conducted to compare the finite sample performance of the new method with those delivered by the normal approximation and the block bootstrap approach. [source] Beyond Point and Level Systems: Moving Toward Child-Centered ProgrammingAMERICAN JOURNAL OF ORTHOPSYCHIATRY, Issue 1 2009FAAN, Wanda K. Mohr PhD Many residential treatment facilities and child inpatient units in the United States have been structured by way of motivational programming such as the point and/or level systems. On the surface, they appear to be a straightforward contingency management tool that is based on social learning theory and operant principles. In this article, the authors argue that the assumptions upon which point and level systems are based do not hold up to close empirical scrutiny or theoretical validity, and that point and level system programming is actually counterproductive with some children, and at times can precipitate dangerous clinical situations, such as seclusion and restraint. In this article, the authors critique point and level system programming and assert that continuing such programming is antithetical to individualized, culturally, and developmentally appropriate treatment, and the authors explore the resistance and barriers to changing traditional ways of "doing things." Finally, the authors describe a different approach to providing treatment that is based on a collaborative problem-solving approach and upon which other successful models of treatment have been based. [source] The development and standardization of the Children Activity Scales (ChAS-P/T) for the early identification of children with Developmental Coordination DisordersCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 6 2006S. Rosenblum Abstract Background Previous studies have emphasized the importance of early identification of children with Developmental Coordination Disorder (DCD) to prevent the development of secondary academic, emotional and social manifestations of the disorder. The aim of this study was to develop a valid parent and teacher questionnaire , the Children Activity Scales for parents (ChAS-P) and for teachers (ChAS-T) , to identify children aged 4,8 years at risk for DCD and to examine the reliability and validity of these questionnaires. Methods The questionnaires' content and face validity were established, and then cut-off scores were determined based on responses of 355 teachers and 216 parents. Internal consistencies were also calculated. Factor analyses were performed, and construct validity was determined by examining the questionnaires' ability to discriminate between 30 children aged 5,6.5 years diagnosed with DCD and 30 typically developing children. Concurrent validity was examined by comparing questionnaire scores with those of the Movement Assessment Battery for Children (M-ABC). Results High values were obtained for internal consistency (0.96,0.94) for the ChAS-T and the ChAS-P respectively. Factor analysis revealed four distinct factors within the ChAS-P and three within the ChAS-T, reinforcing the theoretical validity of the items selected and appropriateness for identifying DCD. Construct validity was indicated by finding significant differences between the groups' scores on the ChAS-T and the ChAS-P. Significant correlations between the children's scores on the questionnaires and those of the M-ABC confirmed their concurrent validity. Conclusions Initial results suggest that the ChAS-T and Chas-P are reliable tools to identify children at risk for DCD. [source] | ||||||||||