Intrinsic Motivation Inventory (IMI) is a multidimensional measurement grounded on the Self-Determination Theory (SDT) used in assessing the subjective experiences of participants when developing an activity. The aim of this study is to analyze the characteristics of IMI among Portuguese students, testing four organizational models (unidimensional, multidimensional, hierarchical and bi-factor). A total of 3685 students from the 5^th to the 12^th grades (50.4% boys) participated in the study (M = 13.67, SD = 2.26). Two versions of IMI were used (First Language and Mathematics) with twenty-one items distributed over five subscales: Enjoyment, Perceived Competence, Pressure/Tension, Perceived Choice and Value/Utility. The confirmatory factor analysis corroborated the multidimensionality of intrinsic motivation, and that the bi-factor model presented the best fit indexes. This model showed the existence of one general factor, resulting from the contribution of all individual dimensions and the particularities of most of them. Furthermore, results also highlighted satisfactory reliability scores both through Cronbach's alpha scores and Composite reliability scores. These results indicate that this scale is appropriate to evaluate the underlying constructs of the theoretical model of SDT and allows for the calculation of a global measure of intrinsic motivation, as well as specific measures for their predictors.

The Achievement Emotions Questionnaire (AEQ) is a self-report instrument developed to measure the emotions of students in academic situations. The main purpose of this research was to adapt and validate this questionnaire to assess pre-adolescents' class- and test-related emotions towards mathematics. The participants were 1515 Portuguese students from grades 5 and 7 (age range 10–13 years). Confirmatory factor analyses and descriptive statistics confirm the reliability and internal validity of the AEQ for Pre-Adolescents (AEQ-PA), providing evidence that the AEQ-PA is an effective instrument to assess pre-adolescent achievement emotions towards mathematics classes and tests.

The main purpose of this research is to analyse what strategies are pursued in order to protect self-esteem when it is threatened by a negative self-evaluation of school competence. Participants were 838 secondary-school students from the seventh to the ninth grades. Data were collected using Harter's Self-Perception Profile for Adolescents, together with a Scale of Attitudes towards School. Our results show that there are significant differences between the self-esteem enjoyed by successful and unsuccessful students in the seventh grade; such differences disappear in the eighth and ninth grades. They also reveal success-related differences in domain-specific self-evaluation. We also found that students with low levels of academic achievement attribute less importance to school-related areas and reveal less favourable attitudes towards school. We discuss these results in terms of Harter's self-esteem model and Robinson and Tayler's self-esteem protection model.