Motivation is considered a variable with a great of influence in educational settings (Baena-Extremera et al., 2013). One of the most important and widely used research perspectives to study motivation in sports and the educational settings is Self-Determination Theory (SDT) (Deci and Ryan, 1985; Deci et al., 1991). Motivation in relation to self-determination is understood as a continuum through which a participant's behavior is ranked according to their degree of self-determination. In 1995, Briere and collaborators created the Echelle de Motivation dans les Sports (EMS) in order to assess self-determination in sports. This instrument was created based on the Academic Motivation Scale (AMS; Vallerand et al., 1992), which was the English language version of l'Echelle de Motivation en Education (EME; Vallerand et al., 1989).
The EMS measures the three types of intrinsic motivation (knowledge, achievement and stimulating experiences), three of the four types of extrinsic motivation, namely identified, introjected and external regulation (leaving out integrated external motivation as suggested by Briere et al., 1995 and Pelletier et al., 1995a) and finally, A-motivation. The EMS scale has 28 items and 7 subscales with four items each. It was translated into English by Pelletier et al. (1995a) as the Sport Motivation Scale (SMS). With regard to the validity and reliability of the SMS, factor analytic studies have supported the 7-factor structure, with supporting by Doganis (2000) in Greece, Burtscher et al. (2011) in Germany, Bara et al. (2011) in Brazil, and Nunez et al. (2005) in Spain. In physical education, researchers such as Moreno et al. (2008, 2009a, 2009b) used the 7-factor SMS by Nunez et al. (2006) with Spanish high school students and obtained good consistency, reliability and fitness indicators.
There remains some discussion on what model constitutes the best fit to explain data. Li and Harmer (1996) and Ntoumanis (2001) found that a 5-factor model produced a better fitting model than a 7-factor model. These authors subsumed the three types of intrinsic motivation into one and considered it as one sole dimension. Accordingly, the scale was composed of 5 dimensions: intrinsic motivation, identified regulation, introjected regulation and external regulation extrinsic motivation and A-motivation. Further, Mallett et al. (2007) found that a 6-factor model of the SMS version demonstrated acceptable fit. Finally, Guzman et al. (2006) in Spain concluded that the results obtained by analyzing intrinsic motivation, extrinsic motivation and A-motivation separately showed better fitness indices than the complete model. Therefore, for some authors the best model would be one composed of a structure of 3-factor or motivational dimensions (Alexandris et al., 2002; Zahariadis et al., 2005).
The fact that the physical education research carried out in Spain has always use the version of SMS for sports (see e.g. Moreno et al., 2008; 2009a; 2009b) is an essential aspect that should be highlighted; however, all these studies point out that the instrument has been adapted to physical education, but no included results of reliability or validity. That said, there are currently no published studies in Spain that have tested the psychometric properties of the SMS adapted to PE, such studies exist in other countries like Greece, for instance (Zahariadis et al., 2005).
Balaguer et al. (2007) have recently analyzed the 3, 5 and 7-factor structures in sports and found the 7-factor model showed the best fit. In general, the various studies analyzing the psychometric properties of the SMS scale have shown adaptation and fitness problems in the confirmatory factor analysis supporting the different 3, 5 and 7-factor theoretical models. There are two problems: one is lack of factor validity (Riemer et al., 2002), the other is low internal consistency (Martin and Cutler, 2002; Pelletier et al., 1995a; Raedeke and Smith, 2001). These problems are probably the result of the inherent difficulty in searching for the correct words to convey the essence of the different types of motivation. This might have affected the process of translating the original EMS French version into English (SMS), contributing perhaps to a loss of meaning (Mallett et al., 2007).
In view of all the above and bearing in mind the absence of studies in the field of education, it is necessary to carry out an analysis of the three models from a physical education perspective in order to identify the model which best adapts itself to this area for future research. Therefore, the object of our study is to provide evidence on the dimensionality of the Spanish version of the SMS adapted to physical education in a sample of teenage high school students by means of confirmatory procedures. The psychometric properties of the three hypothesized SMS models (three, five and seven-factor; Figure 1) were analyzed, to this end we carried out (a) a study of the factor structure of each model with confirmatory factor analysis (CFA), (b) an assessment of internal consistency using Cronbach's alpha, composite reliability coefficient and average variance extracted, (c) a determination of the model with the best data fitness and (d) an assessment of convergent validity.
A total number of 758 high school students from the Murcia region in Spain (347 males = 45.8%; 411 females = 54.2%) participated in this study. Age ranged from 13 to 18 years old (M = 15.22; SD = 1.27), median age for males being 15.2 (SD = 1.29 and 15.18 (SD = 1.26) for females.
Sport Motivation Scale (SMS). The original scale was called Echelle de Motivation dans les Sports (EMS; Briere et al., 1995) and was translated to English by Pelletier et al. (1995a) with the name Sport Motivation Scale (SMS); psychometric properties similar to those in the French version were obtained. The Spanish version validated by Balaguer et al. (2007) and adapted to physical education was used, according preliminary exploration of Granero-Gallegos and Baena-Extremera (2013). The answers were scored on a scale of polytomous items and ranged from 1 (totally disagree) and 7 (totally agree). Participants' socio-demographic data was also collected.
Learning and Performance Orientations in Physical Education Classes Questionnaire (LAPOPECQ) (Papaioannou, 1994): We used the Spanish version (Cervello et al., 2002) to assess the perception on the part of students of the motivational climate in PE lesson, and thus, contrast it with the motivation. It is composed of 27 items and has two dimensions: learning motivational climate (13 items) and performance motivational climate (14 items). The answers were collected on a polytomous scales with scores from 0 (totally disagree) to 10 (totally agree). Recent studies with teenagers in an educational context have proved the reliability and internal validity of the factor structure in two first-order subscales (Moreno et al., 2011), internal consistency values of ([alpha]) >0.75 were obtained. In our study, the internal consistency of the task climate subscale was a = 0.93, average variance extracted (AVE) = 0.83 and composite reliability = 0.98, and that of ego climate was a = 0.87, AVE = 0.75, composite reliability =...