Abstract
Adaptation to basque of a verbal ability, test. The adaptation of psychological tests is a process wich goes beyond the study of the linguistic quality of translation. It is a process that requires the assessment of the metric equivalence between scores, and therefore, a study of the possible bias. In this work the adaptation to Basque of a verbal ability test is studied. The impossibility of using item response theory models has led to the need to utilise alternative detection procedures of differential item functioning. The high percentage of ítems with differential functioning, together with the high correlation between the Mante-Haenszel statistic and Sibtest as well as the low correlation of the logistic iterative regression with previous ones, and also the close relationship between the differential functioning the kind of task associated with each item can be outlined as the most relevant results.