÷ÈÓ°Ö±²¥ & PIRLS International Study Center. (2017). PIRLS 2016 achievement scaling methodology. In M. O. Martin, I. V. S. Mullis, & M. Hooper (Eds.), Methods and Procedures in PIRLS 2016 (pp. 11.1-11.9). Retrieved from Boston College, ÷ÈÓ°Ö±²¥; PIRLS International Study Center website: /publications/pirls/2016-methods/chapter-11.html