ADNI data is made available to researchers around the world. As such, there are many active research projects accessing and applying the shared ADNI data. To further encourage Alzheimer’s disease research collaboration, and to help prevent duplicate efforts, the list below shows the specific research focus of the active ADNI investigations. This information is requested annually as a requirement for data access.
| Principal Investigator | |
| Principal Investigator's Name: | Jonathan Rubright |
| Institution: | University of Delaware |
| Department: | Education |
| Country: | |
| Proposed Analysis: | Parameter estimation in Item Response theory (IRT) is one of the major foci of psychometric research. Common problems in estimation include the Neyman-Scott problem, estimation of extreme abilities, and different program user interfaces. The goal of our project is to compare IRT model parameter estimates between MML, Bayesian MCMC and Variational Bayesian Approximation Estimation methods on skewed, simulated data. Additionally, we want to explore how these methods perform using skewed real data. An interesting scale for this work would be the Geriatric Depression Scale. This scale, commonly used to measure depression in older adults, is almost always skewed: most patients report little or no depression. Our project is a psychometric methods paper that would use de-identified GDS data solely to compare the performance of different IRT estimation techniques on skewed real data. |
| Additional Investigators | |
| Investigator's Name: | Ratna Nandakumar |
| Proposed Analysis: | Parameter estimation in Item Response theory (IRT) is one of the major foci of psychometric research. Common problems in estimation include the Neyman-Scott problem, estimation of extreme abilities, and different program user interfaces. The goal of our project is to compare IRT model parameter estimates between MML, Bayesian MCMC and Variational Bayesian Approximation Estimation methods on skewed, simulated data. Additionally, we want to explore how these methods perform using skewed real data. An interesting scale for this work would be the Geriatric Depression Scale. This scale, commonly used to measure depression in older adults, is almost always skewed: most patients report little or no depression. Our project is a psychometric methods paper that would use de-identified GDS data solely to compare the performance of different IRT estimation techniques on skewed real data. |