Sample Attrition

2021 ◽  
pp. 4355-4355
Keyword(s):  
Sample Attrition

Are There Test Administrator Effects in Large-Scale Educational Assessments?

Methodology ◽  
2007 ◽  
Vol 3 (4) ◽  
pp. 149-159 ◽  
Author(s):  
Oliver Lüdtke ◽  
Alexander Robitzsch ◽  
Ulrich Trautwein ◽  
Frauke Kreuter ◽  
Jan Marten Ihme
Keyword(s):  
Large Scale ◽  
International Student ◽  
Student Assessment ◽  
Student Groups ◽  
Mathematics Scores ◽  
International Student Assessment ◽  
Sample Attrition ◽  
Educational Assessments ◽  
Test Administrator ◽  
Practical Implications

Abstract. In large-scale educational assessments such as the Third International Mathematics and Sciences Study (TIMSS) or the Program for International Student Assessment (PISA), sizeable numbers of test administrators (TAs) are needed to conduct the assessment sessions in the participating schools. TA training sessions are run and administration manuals are compiled with the aim of ensuring standardized, comparable, assessment situations in all student groups. To date, however, there has been no empirical investigation of the effectiveness of these standardizing efforts. In the present article, we probe for systematic TA effects on mathematics achievement and sample attrition in a student achievement study. Multilevel analyses for cross-classified data using Markov Chain Monte Carlo (MCMC) procedures were performed to separate the variance that can be attributed to differences between schools from the variance associated with TAs. After controlling for school effects, only a very small, nonsignificant proportion of the variance in mathematics scores and response behavior was attributable to the TAs (< 1%). We discuss practical implications of these findings for the deployment of TAs in educational assessments.

scholarly journals Potential value of the current mental health monitoring of children in state care in England

BJPsych Open ◽  
2018 ◽  
Vol 4 (6) ◽  
pp. 486-491 ◽  
Author(s):  
Christine Cocker ◽  
Helen Minnis ◽  
Helen Sweeting
Keyword(s):  
Mental Health ◽  
Missing Data ◽  
Mental Health Problems ◽  
Population Level ◽  
Cross Sectional ◽  
Data Set ◽  
Looked After Children ◽  
Education Data ◽  
Sample Attrition ◽  
Aggregate Population

BackgroundRoutine screening to identify mental health problems in English looked-after children has been conducted since 2009 using the Strengths and Difficulties Questionnaire (SDQ).AimsTo investigate the degree to which data collection achieves screening aims (identifying scale of problem, having an impact on mental health) and the potential analytic value of the data set.MethodDepartment for Education data (2009–2017) were used to examine: aggregate, population-level trends in SDQ scores in 4/5- to 16/17-year-olds; representativeness of the SDQ sample; attrition in this sample.ResultsMean SDQ scores (around 50% ‘abnormal’ or ‘borderline’) were stable over 9 years. Levels of missing data were high (25–30%), as was attrition (28% retained for 4 years). Cross-sectional SDQ samples were not representative and longitudinal samples were biased.ConclusionsMental health screening appears justified and the data set has research potential, but the English screening programme falls short because of missing data and inadequate referral routes for those with difficulties.Declaration of interestNone.

The course of depression in the elderly: a longitudinal community-based study in Australia

1997 ◽  
Vol 27 (1) ◽  
pp. 119-129 ◽  
Author(s):  
A. S. HENDERSON ◽  
A. E. KORTEN ◽  
P. A. JACOMB ◽  
A. J. MACKINNON ◽  
A. F. JORM ◽  
...  
Keyword(s):  
Depressive Symptoms ◽  
Cognitive Decline ◽  
Service Use ◽  
Community Sample ◽  
The Elderly ◽  
Activity Levels ◽  
Sample Attrition ◽  
Poor Social Support ◽  
Icd 10 ◽  
Depressive States

Background. We report the outcome of depressive states after 3-4 years in a community sample of the elderly.Methods. A sample of 1045 persons aged 70+ years in 1990–1 was re-interviewed after 3·6 years.Results. Mortality (21·7%) and refusal or non-availability (10·4%) were higher in those who initially had had a diagnosis or symptoms of depression. Of those with an ICD-10 depressive episode in 1990–1, 13% retained that diagnosis. Of those who were not depressed initially only 2·5% had become cases. Depression was unrelated to age or apolipoprotein E genotype. The best predictors of the number of depressive symptoms at follow-up was the number at Wave 1, followed by deterioration in health and in activities of daily living, high neuroticism, poor current health, poor social support, low current activity levels and high service use. Depressive symptoms at Wave 1 did not predict subsequent cognitive decline or dementia.Conclusions. Non-random sample attrition is unavoidable. ICD-10 criteria yield more cases than other systems, while continuous measures of symptoms confer analytical advantages. Risk factors for depressive states in the elderly have been further identified. The prognosis for these states is favourable. At the community level, depressive symptoms do not seem to predict cognitive decline, as they do in referred series.

Energy index of working units abrasion of agricultural machinery in contact with abrasives

10.12737/2434 ◽  
2014 ◽  
Vol 8 (4) ◽  
pp. 55-60
Author(s):  
Белинский ◽  
Aleksandr Belinskiy ◽  
Семушкин ◽  
Nikolay Semushkin ◽  
Зиганшин ◽  
...  
Keyword(s):  
Technology Development ◽  
Efficient Production ◽  
Energy Index ◽  
Agricultural Machinery ◽  
Sample Attrition ◽  
Wide Range ◽  
The Russian Federation ◽  
Energy Saving Technology ◽  
Selection For ◽  
Agricultural Machines

One of the priority directions of science and technology development in the Russian Federation are: energy efficiency, energy saving, technology of energy-efficient production. In the agriculture the most energy-intensive processes are in tillage, shredded stems by fodder chopper machines and etc. The working units of agricultural machinery exposed to abrasion, which leads to mechanical wear of the material, that occurs as a result of cutting and scratching action on him solids in free or clamped. The obtained formula for determining the energy index of the sample is a rational, because it is derived from the laws of mechanics. The proposed methodology and the resulting energy abrasion index is recommended for the calculation of required energy for wear, when determining the reliability and life of the working units of the various machines, interacting with an abrasive material. The numerical values of the energy index of the sample of working unit abrasion some agricultural machines are in a wide range from 0.416 kJ per kilogram in the spiral of equalizer roller of tillage machines to 1.716 to kJ per kilogram in the tooth of harrows BZS-1.0. The device is suitable for the determination by express - method (the duration of control time on sample attrition is 10 times smaller than a standard device) power indicator abrasion of tested materials in their selection for the production of cheaper and more wear-resistant working units of agricultural machinery, as well as after heat treatment, sputtering work surfaces by wearproof materials.

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