Journal Published Online: 26 October 2015
Volume 44, Issue 5

Models of Intra- and Interclass Correlation Test Mean-Score Reliability



A mean-score reliability of a test in a form of repeated trials with the same measurement equipment is estimated using an intraclass correlation coefficient varied within -∞ and 1. The research aims to outline a method of estimation of the retest mean-score reliability coefficient adequate to its theoretical model, i.e., without negative values. The idea is: (1) to include all the scores obtained in the test–retest of the group of subjects to a united sample, and (2) to estimate corresponding true scores as individual means scores and include them to another sample. A proposed reliability score coefficient is derived as a ratio of a sum of squares of the individual means scores multiplied by a number of repeated trials to a total sum of squares. The method proposed in the work brings values of the mean-score reliability coefficient into the interval defined in the classic theory of test reliability: 0 to 1. The approach is illustrated with numerical examples.

Author Information

Zanevskyy, Ihor
Kazimierz Pulaski Technological and Humanistic Univ., Radom, PL
Zanevska, Lyudmyla
Lviv State Univ. of Physical Culture, UA
Pages: 9
Price: $25.00
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Stock #: JTE20140363
ISSN: 0090-3973
DOI: 10.1520/JTE20140363