Rasch/Guttman-based Scenario (RGS) Scale: Capturing Complex Constructs with enhanced interpretability and actionability
The RGS approach integrates Rasch measurement principles and Guttman’s facet theory design to develop an instrument that measures a single, unidimensional construct. The RGS approach combines the specificity and invariance features of Rasch measurement with the systematic theory-building tools of facet design that provide a greater level of interpretability. The resulting RGS scale offers rich, qualitative descriptions of what individuals “look like” along various levels
of a construct continuum. First developed by Dr. Larry Ludlow at Boston College to measure engagement in later life activities, the RGS approach has been applied to a variety of constructs. For instance, using the RGS approach, the 15-item Teaching Equity Enactment Scenario (TEES) Scale was developed to capture the complexity of equity-centered teaching practice. Built on the initial instrument development results, multiple studies using both quantitative and qualitative methods have been pursued to validate, enhance, and shorten the scale among teachers in the U.S., New Zealand, and Singapore contexts.
Publications drawn from the work of the TEES Scale
Chang, W.-C. (in press). Measuring the complexity of equity-centered teaching practice: Enhancement and validation of a Rasch/Guttman scenario scale. Journal of Applied Measurement, 22(2), 35-59.
Ludlow, L. H., Reynolds, K., Baez-Cruz, M., & Chang, W.-C. (2021). Enhancing the interpretation of scores through Rasch-based scenario-style items. In U. Luhanga & G. Harbaugh (Eds.), Basic elements of survey research in education (pp. 673-718). Information Age Publishing.
Ludlow, L. H., Baez-Cruz, M., Chang, W.-C., & Reynolds, K. (2020). Rasch/Guttman Scenario (RGS) scales: A methodological framework. Journal of Applied Measurement, 21(4), 361-378.
Chang, W.-C., Ludlow, L. H., Grudnoff, L., Ell, F., Haigh, M., Hill, M., & Cochran-Smith, M. (2019). Measuring the complexity of teaching practice for equity: Development of a scenario-format scale. Teaching and Teacher Education, 82, 69-85.
Awards received for the development of the TEES Scale
2021 Georg William Rasch Early Career Award
American Educational Research Association/the Rasch Special Interest Group
2017 George Madaus Graduate Student Research Award
Lynch School of Education and Human Development, Boston College
Grants received to develop the TEES Scale
2019 – 2020 Education Research Funding Programme Planning Grant
National Institute of Education, Singapore (Principal Investigator)
2016 Summer Dissertation Development Grant
Lynch School of Education and Human Development, Boston College