Decreases in Posttest Variance and The Measurement of Change
نویسندگان
چکیده
A Monte Carlo study was used to evaluate the effects of reductions in posttest variance on several methods for detecting predictors of change in a two-wave design. When the predictor was dichotomous, the analysis of covariance approach was compared to the analysis of variance on difference scores. For a continuous predictor, partial correlations, difference score correlations with the predictor and latent change correlations with the predictor in structural equation growth models were used. When posttest variance decreased (e.g., ceiling effect) difference scores lost power, while the power of regression based methods (analysis of covariance and partial correlations) and structural equation measures of change were unaffected.
منابع مشابه
Comparison of the Effect of Visual and Auditory Distractions on the Physiological Parameters during the Dressing Change Procedure in 6-12-Year-Old Children
Background and Objective: As pain impulses ascend from the spinal cord, the autonomic nervous system is stimulated and leads to changes in physiological parameters. This study aimed to compare the effect of visual and auditory distractions on the physiological parameters during dressing change procedure in children aged 6-12 years. Materials and Methods: This blinded clinical trial was conduct...
متن کاملPretest-posttest designs and measurement of change.
The article examines issues involved in comparing groups and measuring change with pretest and posttest data. Different pretest-posttest designs are presented in a manner that can help rehabilitation professionals to better understand and determine effects resulting from selected interventions. The reliability of gain scores in pretest-posttest measurement is also discussed in the context of re...
متن کاملبررسی زاویه بتا در منحنی جریان - حجم در بیماران مبتلا به انسداد راههای هوائی
It is known that spiromentry is the most conventional method to determine pulmonary function. In spirometry, the shape of flow-volume loop is the most helpful finding to evaluate pulmonary dysfunction. Obstruction is best demonstrated by the slope of the descending portln of the exhalation curve. Measurement of fJ-angle is helpful for determination of this slope. fJ-angle is defined by 3 points...
متن کاملSimultaneous Monitoring of Multivariate Process Mean and Variability in the Presence of Measurement Error with Linearly Increasing Variance under Additive Covariate Model (RESEARCH NOTE)
In recent years, some researches have been done on simultaneous monitoring of multivariate process mean vector and covariance matrix. However, the effect of measurement error, which exists in many practical applications, on the performance of these control charts is not well studied. In this paper, the effect of measurement error with linearly increasing variance on the performance of ELR contr...
متن کاملThe Effect of Teaching Philosophy on Metacognitive and Irrational Beliefs of Male Students of Elementary School
Background: Philosophy for children (P4C) is a wonderful way of bringing teachers and children together to discuss crucial topics. It has many benefits for both groups. This study aimed to evaluate the teaching process-approach of P4C on students’ metacognitive and irrational beliefs by using an experimental design with the pretest-posttest and control group. Methods: The statistical populatio...
متن کامل