Fitness portfolio calibration for first- through sixth-grade children.
The purpose of this study was to develop and calibrate health-relatedfitness portfolios for 1st-6th grade students using the many-faceted Rasch model, and examine advantages and disadvantages of a portfolio assessment system based on Rasch calibration. Nine hundred ninety-five studentsfrom 23 schools infirst-sixth grade, who completed three-six of nine health-related fitness portfolios, participated in this study. Ten physical education teachers performed the grading across various portfolios and grade levels. Students'portfolios were rated using 23 predeveloped rubrics, and their scores linked through several common portfolios that were used across schools. The rating scores were analyzed using the many-faceted Rasch model, with four defined facets: portfolio, rubric, student, and rater The model-data fit was very good, and a consistent grade difference wasfound, that is, older students scored higher in fitness knowledge than younger ones. With Rasch calibration, measurement problems in conventional portfolio assessments can be eliminated, and a valid and reliable assessment system can be developed. In addition, several other measurement advantages are provided by Rasch calibration (e.g., related facets can be examined and controlled simultaneously). A large sample size and a more complex process, however, are required in the calibration stage of developing such a system using the Rasch model.