"A_Tempo" is a research project that is currently under development in Galicia, an autonomous community of Spain. Its main aim is to propose an effective universal screening procedure for early identification of developmental disorders in children from zero to three years of age who attend Galician pre-primary schools.…

Formulas are presented for decision reliability and for classification validity for mastery/nonmastery decisions based on criterion referenced tests. Two item parameters are used: the probability of a master answering an item correctly, and the probability of a nonmaster answering an item incorrectly. The theory explores the relationships of…