Zero Error and Practice Effects in Moray House English Quotients

S ummary . Ninety‐six children in two Dublin primary schools were each set six tests of the Moray House English Test series. The purpose of the experiment was twofold: ( a ) to discover whether Moray House English Tests vary in difficulty level and to measure the variation, or zero error, if it exists; ( b ) to measure the extent to which Moray House English Quotients are influenced by practice. The particular interest of making measurement ( b ) in Dublin was that the children were, to begin with, totally unfamiliar with such tests whereas for many years British children of the same age cannot be considered to have been so. However, gains with practice were not greater in this than in previously reported investigations. The existence of zero error in Moray House English Tests was established. The finding is discussed and related to similar findings with other tests and ah attempt is made to discover the reasons for the phenomenon.