In this paper, adaptation and validation of a scale measuring how prepared preservice elementarymathematics teachers perceive themselves to teach mathematics were explained. Exploratory and confirmatoryfactor analyses and test, item and option analyses according to Item Response Theory were conducted as proofsof validity. Cronbach’s alpha and Mc Donald’s omega were calculated both for ordinal and interval scales andfor point estimates and confidence intervals. The findings were evaluated by an expert group and the researchersbut no single perfect result was sought. Due to the subjective nature of some of the analyses and the followingdecisions in this type of studies, the analyses were made for all possible alternatives, the findings were p...