Using relative improvement over chance (RIOC) to examine agreement between tests: Three case examples using studies of developmental coordination disorder (DCD) in children

Although statistics such as kappa and phi are commonly used to assess agreement between tests, in situations where the base rate of a disorder in a population is low or high, these statistics tend to underestimate actual agreement. This can occur even if the tests are good and the classification of subjects is adequate. Relative improvement over chance or RIOC is a statistic that can correct for this bias; however, it is not yet commonly used …