School motivation inventory: development of a short scale in the Portuguese educational context

The present study focuses on the development of a short scale of The Facilitating Conditions Questionnaire adapted to the Portuguese secondary school. Based on the McInerney’s School Motivation Inventory (McInnerney et al., 1997), a short form of the instrument with 31 items assesses the following motivation facilitating conditions: valuing school (5 items), affect to school (3 items), influence of teachers (5), positive (6 items) and negative (5 items) parental influence and negative (4 items) and positive (4 items) peer influence (4 items). The sample included 605 students from the secondary school, aged between 14 and 18 years (M = 15.76, SD = 1.14), mostly female (58.7%), attending to different academic courses. Overall, the short version of instrument exhibited good psychometric qualities: good internal consistency (Cronbach’s alpha = .85), the extraction of 7 factors through exploratory factor analysis that explain 55.1% of the total variance and the confirmation of this structure by confirmatory factor analysis with good fit indices (Ȥ2 / 384 = 1.79, CFI = .94, TLI = .93 and RMSEA = .05). The results indicated adequate correlations between the dimensions, with the strongest association between the positive parental influence and negative peer influence (r = -.53) and the lowest between positive peer influence and negative parental influence (r = -.19). The scale also revealed adequate construct validity with the General Achievement Goals Orientation Scale (McInnerney et al., 1997; adapted to the Portuguese context by Gomes et al., 2018), presenting the strongest association between the positive parental influence’s dimension and global motivation (r = .66) and general mastery (r =.66) and the lowest associations between the general social dimension and the valuing school (r =.15) and positive peer influence (r =.16) dimensions. These results support the psychometric qualities of the instrument, not excluding, however, the need to replicate this study in larger samples and in other contexts.