Reliability and Comparability of TOEFL iBT™‑ Scores
ETS has always been committed to the quality of its test scores. As an ETS assessment program, TOEFL® strives to ensure score reliability and comparability through strict adherence to guidelines and practices established for the development and operational implementation of its products and services. Evidence of score reliability and comparability is important because it suggests that test scores will have the same meaning across test forms. ETS strives to ensure that the test scores of the TOEFL Internet based test (iBT) are reliable and comparable by:
• implementing and adhering to standardized administration and test security procedures
• using detailed test specifications to guide test development
• monitoring score reliability and generalizability
• employing an appropriate scale for reporting scores
• using equating and other means to maintain comparable scores across test forms