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Psychometric Services
Contributing Diverse Experience
DRC understands that every client’s measurement needs are unique. In order to best deliver custom solutions to meet your state’s testing needs, we have developed a synergistic team of highly qualified, in-house psychometric experts. Their collective knowledge spans a variety of measurement models, methodologies, and industries. Key Psychometric Services team members include:
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Mr. David Chayer,
Vice President of Psychometric Services, oversees all psychometric activities at DRC and ensures that all methodologies and processes are valid and legally defensible. During his 20 years in test design and psychometrics, he has become an expert in the development of computer-based measurement instruments that have met exacting standards in 17 states. |
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Dr. Yi Du, Senior Psychometrician, has over 12 years of experience in psychometrics for large-scale, statewide testing programs. Dr. Du is a highly respected technical consultant who has served both at the state and local level. |
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Ms. Pamela Hermann, Senior Psychometrician, has extensive experience in data analysis and psychometrics. Her areas of expertise include item analysis, test construction, item calibration, equating, and scaling, as well as licensure and certification testing. |
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Dr. Ronald Mead,
Senior Psychometrician, is a nationally recognized expert in the application of Rasch methodologies, having conducted seminal research with Dr. Ben Wright and Dr. Geoff Masters. Dr. Mead has more than 32 years of experience in psychometric research and activities related to statewide testing programs. |
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Dr. Richard Smith, Senior Psychometrician, has extensive experience in all aspects of psychometrics, with more than 20 years in the field. Dr. Smith is the founding editor of the Journal of Applied Measurement, the most authoritative source on Rasch research. |
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Dr. Michael Yoes,
Senior Psychometrician, has far-ranging experience in psychometrics. For over 20 years, Dr. Yoes has been involved in high-stakes education assessment, computer-based testing, and research related to statewide testing. |
A Complete Range of Psychometric Services
At DRC, we build customized testing solutions that apply state-of-the-art technology and adhere to the Standards for Educational and Psychological Testing. Our psychometric services include:
| Item analysis |
| Generalizability |
| Differential Item Functioning (DIF) |
| Item and scaling drift |
| Scaling and equating |
| Customized reporting |
| Standard setting |
| Special studies |
Scaling and Equating
Beyond good design and implementation, a critical measure of a testing program’s success depends on the ability to communicate results quickly, accurately, and clearly. DRC’s psychometricians are proficient in key industry-accepted scaling and equating models, including Rasch and three-parameter IRT. They can recommend and define the best model for your particular assessments.
DRC uses WINSTEPS© to generate the item parameters used for review and test form construction. This calibration software is commercially available and widely used in the testing industry. It facilitates a collaborative effort in which our psychometricians can train you and your staff in the scaling and equating process, allowing you to then perform an independent check and verification of the process.
Standard Setting
DRC’s psychometricians can conduct standard-setting studies using both examinee- and test-centered models. For example, the Modified-Angoff procedure, Bookmark, Borderline and Contrasting Group, and Body of Work are among the test-centered procedures we have implemented for our clients. In addition, we pioneered procedures for setting standards for non-standard student populations, such as LEP and IEP students assessed within an Alternative Portfolio system.
Forms Construction
To ensure that forms construction is both efficient and error-free, DRC designed and developed First Form©, a technical infrastructure for test assembly. First Form enables us to narrow the set of all possible test forms to a manageable subset of psychometrically acceptable forms. This powerful tool interfaces with WINSTEPS© and third-party statistical programs, and features flexible constraint handling that adheres to industry best practices.
Special Studies
Because the testing industry constantly poses new challenges, our Psychometric Services staff is always ready to assist you in defining a research question or conducting special studies to deliver the information you need to solve problems, present to the Board, or provide additional documentation of the psychometric quality of your assessments.
With the diverse knowledge, experience, and background of our psychometric staff we can match the right expert to your project. At the same time, we leverage the unique strengths and synergies of the others on our team to contribute to your success.
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