scholarly journals Replicating analyses of item response curves using data from the Force and Motion Conceptual Evaluation

Author(s):  
Connor J. Richardson ◽  
Trevor I. Smith ◽  
Paul J. Walter
1992 ◽  
Vol 17 (3) ◽  
pp. 251-269 ◽  
Author(s):  
James H. Albert

The problem of estimating item parameters from a two-parameter normal ogive model is considered. Gibbs sampling (Gelfand & Smith, 1990) is used to simulate draws from the joint posterior distribution of the ability and item parameters. This method gives marginal posterior density estimates for any parameter of interest; these density estimates can be used to judge the accuracy of normal approximations based on maximum likelihood estimates. This simulation technique is illustrated using data from a mathematics placement exam.


2019 ◽  
Vol 76 (Suppl 1) ◽  
pp. A28.2-A28
Author(s):  
Roel Vermeulen

Occupation and employment is a major determinant of health and healthy aging. Despite the temporal increase in time spent in employment and profound changes in working life, there is limited coordinated research on occupation and health.We recently estimated that in Europe alone there is information available on more than 30 million individuals that could be used to study the association between working life and health. However, lack of standardization, inability to code large numbers of job-entries and inabilities to share data have hindered progress. In order to unlock the vault of occupational-health information novel ways of data acquisition, standardization, pooling and analyses have to be developed and implemented. The ability of pooling studies would greatly improve occupational health studies by increasing sample size for robust inference, and would allow risk stratification, identification of new risks, exploration of interactions with work and non-work-related factors and detailed analyses on the shapes of the exposure-response curves.In recent years we have seen progress in several different methodological aspects. Currently, new tools are available to collect information on work and work exposures. These include amongst others the use of sensors and mobile phone applications. Standardization of occupational information is essential for comparison of results between studies and for pooling of studies. This could be achieved by using common occupational coding schemes, use of automatic coding instruments and common exposure assessment tools. Virtual pooling of data has become possible by using data-shields which instead of bringing the data to the analyses bring the analyses to the data allowing federated analyses.As part of the OMEGA-NET symposium we will discuss the need for new tools and avenues of how to bring occupational health information together. We will present our inventory of novel tools to aid this process, and will discuss future needs.


2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
M. Elaine Cress ◽  
Yasuyuki Gondo ◽  
Adam Davey ◽  
Shayne Anderson ◽  
Seock-Ho Kim ◽  
...  

Centenarians display a broad variation in physical abilities, from independence to bed-bound immobility. This range of abilities makes it difficult to evaluate functioning using a single instrument. Using data from a population-based sample of 244 centenarians (MAge= 100.57 years, 84.8% women, 62.7% institutionalized, and 21.3% African American) and 80 octogenarians (MAge= 84.32 years, 66.3% women, 16.3% institutionalized, and 17.5% African American) we (1) provide norms on the Short Physical Performance Battery and (2) extend the range of this scale using performance on additional tasks and item response theory (IRT) models, reporting information on concurrent and predictive validity of this approach. Using the original SPPB scoring criteria, 73.0% of centenarian men and 86.0% of centenarian women are identified as severely impaired by the scale's original classification scheme. Results suggest that conventional norms for older adults need substantial revision for centenarian populations and that item response theory methods can be helpful to address floor and ceiling effects found with any single measure.


2020 ◽  
Vol 125 (6) ◽  
pp. 475-480
Author(s):  
Cristan A. Farmer ◽  
Aaron J. Kaat ◽  
Audrey Thurm ◽  
Irina Anselm ◽  
Natacha Akshoomoff ◽  
...  

Abstract Although norm-referenced scores are essential to the identification of disability, they possess several features which affect their sensitivity to change. Norm-referenced scores often decrease over time among people with neurodevelopmental disorders who exhibit slower-than-average increases in ability. Further, the reliability of norm-referenced scores is lower at the tails of the distribution, resulting in floor effects and increased measurement error for people with neurodevelopmental disorders. In contrast, the person ability scores generated during the process of constructing a standardized test with item response theory are designed to assess change. We illustrate these limitations of norm-referenced scores, and relative advantages of ability scores, using data from studies of autism spectrum disorder and creatine transporter deficiency.


2011 ◽  
Vol 36 (6) ◽  
pp. 755-778 ◽  
Author(s):  
Hongwen Guo ◽  
Sandip Sinharay

Nonparametric or kernel regression estimation of item response curves (IRCs) is often used in item analysis in testing programs. These estimates are biased when the observed scores are used as the regressor because the observed scores are contaminated by measurement error. Accuracy of this estimation is a concern theoretically and operationally. This study investigates the deconvolution kernel estimation of IRCs, which corrects for the measurement error in the regressor variable. A comparison of the traditional kernel estimation and the deconvolution estimation of IRCs is carried out using both simulated and operational data. It is found that, in item analysis, the traditional kernel estimation is comparable to the deconvolution kernel estimation in capturing important features of the IRC.


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