Structural equation models with latent variables are sometimes estimated using an intuitive three-step approach, here denoted
factor score regression. Consider a structural equation model composed of an explanatory latent variable and a response latent
variable related by a structural parameter of scientific interest. In this simple example estimation of the structural parameter
proceeds as follows: First, common factor models areseparately estimated for each latent variable. Second, factor scores areseparately assigned to each latent variable, based on the estimates. Third, ordinary linear regression analysis is performed among the
factor scores producing an estimate for the structural parameter. We investigate the asymptotic and finite sample performance
of different factor score regression methods for structural equation models with latent variables. It is demonstrated that
the conventional approach to factor score regression performs very badly. Revised factor score regression, using Regression
factor scores for the explanatory latent variables and Bartlett scores for the response latent variables, produces consistent
estimators for all parameters. 相似文献
Premature infants lack the tactile stimulation they would have otherwise experienced in the womb. Infant massage is a developmentally supportive intervention that has been documented for several decades to have a positive effect on both full term and preterm infants. The purpose of this study was to assess the short and long term benefits of massage on stable preterm infants.
Methods
A quasi experimental design was used, 66 infants were recruited from two university hospitals with tertiary level NICUs; 32 infants received the massage therapy by their mothers. Data collection by a researcher blind to the infants’ group assignments included weight at discharge, pain responses on the PIPP scale at discharge, length of stay in hospital, neuro-developmental outcome (Bayley scores) and breastfeeding duration at 12 months corrected age.
Results
Infants who were massaged had significantly lower scores on the PIPP after a heel-stick compared to before the massage and had lower PIPP scores at discharge compared to the control group. Massaged infants had higher cognitive scores at 12 months corrected age. Weight gain, length of stay, breastfeeding duration and motor scores did not differ between groups.
Conclusion
Stable preterm infants benefit from massage therapy given by their mothers and may be a culturally acceptable form of intervention to improve the outcomes of preterm infants. 相似文献
Knowing the prevalence of low neurocognitive scores for the WISC-IV Canadian normative sample (WISC-IVCDN) is an important supplement for clinical interpretation of test performance. On the WISC-IVCDN, it is uncommon for children and adolescents to have 4 or more subtest scores or 2 or more Index scores ≤ 9th percentile when all scores on the battery are considered simultaneously. As the level of the child's intelligence increases or the number of years of parental education increases, the prevalence of low scores decreases. These results are consistent with existing studies of the base rates of low scores in children and adolescents on pediatric cognitive batteries, including the WISC-IV American normative sample. Tables provided are ready for clinical use. 相似文献
Four pairs of connectionist simulations are presented in which quasi-regular mappings are computed using localist and distributed representations. In each simulation, a control parameter termed input gain was modulated over the only level of representation that mapped inputs to outputs. Input gain caused both localist and distributed models to shift between regularity-based and item-based modes of processing. Performance on irregular items was selectively impaired in the regularity-based modes, whereas performance on novel items was selectively impaired in the item-based modes. Thus, the models exhibited double dissociations without separable processing components. These results are discussed in the context of analogous dissociations found in language domains such as word reading and inflectional morphology. 相似文献
The traditional pre-post treatment difference reflects an incremental notion of change, where a quantity of some psychological function is added to (or subtracted from) a pretreatment quantity. This study presents a complementary, experiential notion of change. Rather than a difference, change is a feeling or experience of having changed, a feeling that one is different than before. Based on a post-treatment interview the Change after Psychotherapy (CHAP) is a method to quantify/rate such ‘differentness’ in terms of how extensively or radically the patient feels having changed. A pre-post quasi-experimental study (N = 49) comparing the CHAP with ratings on the Global Assessment of Functioning, the Karolinska Psychodynamic Profile and the Comprehensive Psychopathological Rating Scale-Self-Affective is reported. The results showed the CHAP to be a reliable, valid and sensitive way to assess an experiential kind of CHAP. 相似文献
Objective: Haemodialysis patients are at risk of serious health complications; yet, treatment non-adherence remains high. Warnings about health risks associated with non-adherence may trigger defensive reactions. We studied whether an intervention based on self-affirmation theory reduced resistance to health-risk information and improved fluid treatment adherence.
Design: In a cluster randomised controlled trial, 91 patients either self-affirmed or completed a matched control task before reading about the health-risks associated with inadequate fluid control.
Outcome measures: Patients’ perceptions of the health-risk information, intention and self-efficacy to control fluid were assessed immediately after presentation of health-risk information. Interdialytic weight gain (IDWG), excess fluid removed during haemodialysis, is a clinical measure of fluid treatment adherence. IDWG data were collected up to 12 months post-intervention.
Results: Self-affirmed patients had significantly reduced IDWG levels over 12 months. However, contrary to predictions derived from self-affirmation theory, self-affirmed participants and controls did not differ in their evaluation of the health-risk information, intention to control fluid or self-efficacy.
Conclusion: A low-cost, high-reach health intervention based on self-affirmation theory was shown to reduce IDWG over a 12-month period, but the mechanism by which this apparent behaviour change occurred is uncertain. Further work is still required to identify mediators of the observed effects. 相似文献