Building a Self-Confidence Scale According to the Item Response Theory for High School Students in Jordan

This study aimed to build self-confidence for high school students in Al-Mafraq Governorate in Jordan following the Item Response Theory (IRT). The scale included its initial version (50) items. To ensure the external validity of the scale, it was reviewed by several experts. According to the experts’ feedback, some items should be deleted or modified. The final version of the scale included (44) items. The scale was further applied to an experimental sample of (310) male and female students to verify psychometricians’ characteristics. Finally, the scale was administered to a sample of (1060) male and female high school students in Al-Mafraq Governorate. Data were collected, coded, and analyzed using statistical programs (SPSS and WINSTEPS). The most important results were the following: the self-confidence measure was one-dimensional, which means it measures only a single dimension. The results further revealed identical to the partial estimation model, and the index of average matching of individuals and the external and internal items approached zero, and the standard deviation approached the correct one. The estimated values of the distinct thresholds for the scale items showed a clear discriminatory ability and the emergence of particular threshold scores on the scale. After deleting the paragraphs that did not fit the study's model, the scale's final version included 39 items. The results also showed that the transfer values of logistical capacity units were within (-2.88 -2.77), within the IRT's accepted range.