Validity and Reliability of Measurement Instrument for Sport Motivation Scale in Professional Athletes in Team Sports of Iran

Motivation represents one of the most important variables in sport. A large number of studies incorporating the SDT framework in the sport domain have confirmed that SDT is appropriate to understanding and promoting optimal motivation in sport. The purpose of this study was to determine the validity and reliability of sport motivation questionnaire. For selecting our sample we use available random sampling, so 200 participants were randomly selected for both male and female of professional athletes on the field of volleyball team, basketball, football, handball, futsal and then completed the questionnaires in a voluntary manner. Cronbach's alpha was used to calculate the reliability and confirmatory factor analysis test was used for studying the validity of the questionnaire. Findings showed that a Cronbach's alpha level for sport motivation was 0.80, which indicates the reliability of the variable is relatively good. And it should be mentioned that Sport motivation scale models used in society of professional athletes of Iranian team was relevant.


Introduction
Regular play and practice of sport activities is associated with a number of positive outcomes, including increased fitness, increased vitality, increased self-esteem, and reduced serious illness [1,2]. Although most people to some extent are aware of the positive outcomes associated with sport activity, many people discontinue their sport participation every year [3]. Accordingly, a significant amount of research has been conducted on motivation in sport for the purpose of understanding why some athletes show an enduring desire to pursue their sport, whereas others quit or lose interest [4].
Motivation and its impact on behavior can be well expressed by self-determination theory which developed by Deci and Ryan [5]. Selfdetermination theory is a macro theory about human motivation that is associated with the development and function of personality in social contexts. The theory analyzes a behavior in which to what the extent human behavior is voluntary or autonomic behavior [5]. Motivation represents one of the most important variables in sport. In fact coaches and athletes agree that motivation is one of the key elements that will facilitate not only performance but also a positive experience in the sport area [6]. A large number of studies incorporating the SDT framework in the sport domain have confirmed that SDT is appropriate for understanding and promoting optimal motivation in sport [7].
Early sport motivation measurement instrument did not adequately measure all types of motivation as explained by SDT and/or presented weak factor structures [e.g. [8,9]]. The original authors of the Sport Motivation Scale (SMS; Pelletier et al.) progresses measurement in contextual sport motivation based on self-determination theory [5]. Since 1995, the SMS has been used extensively in sport motivation research. However, research has identified several limitations of the SMS -theoretically, empirically, and practically. We developed the SMS-6 in response to increase evidence that the SMS required revision, by including four items measuring integrated regulation, replacing of four problematic items, and constructing a composite intrinsic motivation subscale [6].
Mallett et al. [10] stated that sport motivation scale which had been developed earlier should be revised to include a criterion for measuring integrated regulation. Because without this criterion, the scale does not reflect all existing structures within the frame work of selfdetermination theory. Mallett et al. also argued that some cases should be removed from the scale and subscale of intrinsic motivation should be combined in a single measuring criterion. Sport motivation scale have been used in some studies such as studies by [10][11][12][13][14] Kawabata and Mallett [15]. According to the growing interest in studies in the field of sport motivation, a valid measurement instrument is required. So the purpose of this study was determining the validity and reliability of measurement instrument of sport motivation in professional athletes in team sports of Iran.

Participants
The population of this research consist of all professional athletes in team sports (for both men and women) who have competed at least 5 years in volleyball, basketball, futsal, handball, football. The sample consisted of 200 participants who were randomly selected among available sports. They included 114 men and 86 women. The average of age and standard deviation for the men were 22.51 and 4 respectively and those indicators for the women were v23.31, 3.56 respectively that both of the groups completed questionnaires in voluntary manner.

Measurements instrument
Sport Motivation Scale developed by Mallett et al. [10] Motivation is an internal factor that stimulates individual's behavior and leads to a specific direction and coordinates it. Motivation is turning to specific activity and continued it; that may be a physical activity or mentalsocial activity that is measured by sport motivation scale with 7 item Like rt scale. This scale consists of 24 statements and six subscales that include:

A motivation
This means lack of purpose and intentionality in one's action.

External regulation
Which refers to doing actions for obtain rewards or avoid blame by others?

Introjected regulation
This refers to behaviors that are strengthened through internal pressures such as guilt or anxiety.

Identified regulation
That is when person emphasize on behavior and give worth to that behavior.

Integrated regulation
This represents the most independent form of extrinsic motivation that happens when there is heterogeneity between behavior rules and needs, goals and personal confirmed values which are part of the person.

Intrinsic motivation
This means engaging in an activity for itself and for the pleasure and satisfaction derived from participation. Four statements were used for each subscales and for responding to each statement, is used 7 item Like rt scale that range from: completely disagree with degree (1) and completely agrees with the degree (7). The English form of the questionnaire of doping behavior was translated into Persian by specialist and then scale of validity was confirmed by experts in that field. In research by Mallett et al. [10] reliability of questionnaires by counting reliability of Cronbach's alpha coefficient was obtained up to 0.70 In this research Cronbach's alpha coefficient for sport motivation obtain 0.80.

Statistical methods
Statistical methods in this study were both descriptive and inferential statistics. Mean, standard deviation, and frequency tables for summarizing and classifying the raw data were used in descriptive and Cronbach's alpha was used in inferential statistics for calculating validity. Confirmatory factor analysis was used to test the validity of the questionnaire and SPSS software (version 16) was used for data analysis.

Results and Discussion
Results showed that 162 participants among the 200 participant-114 were male and 86 were female-believed that their success in future depends on the their success in sports but 38 women did not believe that their success in future depends on the their success in sports.. Table 1 show descriptive indicators such as mean and standard deviation for all question of sports motivation questionnaire. Findings in Table 1 indicate that Question 2 of intrinsic motivation subscale has highest mean (M=5.54) and Question 4 has the lowest mean (M=4.85). Also, Question 4 of intrinsic motivation subscales has highest standard deviation (SD=1.80) and its second question has the lowest SD (SD=1.57). Question 2 of introjected regulation subscales has the highest mean (M=5.19) and its third question has the lowest mean (M=4.26). Moreover question 3 of introjected regulation subscales has the largest SD (SD=1.90) and its second question has the lowest standard deviation (SD=1.59). Question 4 of identified regulation subscales has highest mean (M=5.25) and its first question has the lowest mean (M=4.86) and question 3 of identified regulation subscales has the highest standard deviation (SD=1.79) and its second Question has the lowest standard deviation (SD=1.46). In addition, question 4 of external regulation subscale has highest mean (M=4.21) and its second question has the lowest mean (M=3.95) and Question 3 of external regulation sub scale has the highest standard deviation (SD=2.07) and its first question the lowest standard deviation (SD=1.71). The question 2 of integrated regulation subscale has the highest mean (M=5.01) and its first question has the lowest mean (M=4.45) and question 1 of integrated regulation subscale has the highest standard deviation (SD=1.88) and its fourth Question has the lowest standard deviation (SD=1.71). Question 2 of a motivation subscale has the highest mean (M=2.72) and its third question has the lowest mean (M=1.97). Also, question 1 of a motivation subscale has the highest standard deviation (SD=1.76) and its third question has the lowest standard deviation (SD=1.35).
Results of Table 2 show the Cronbach's alpha coefficients for the sport motivation variables. Table 3 shows Cronbach's alpha coefficients for dimension of sport motivation. Table 4 shows measurement instrument of sport motivation in standardized estimate. Factor loadings of model in standardized estimate show the effect of each variable or statements in explanation of variance of scores in variable or main factor. For example, factor loading in question 1 in intrinsic motivation is 0.58 In other words; the first question can explain almost 34% of the variance in intrinsic motivation. The amount 0.66 is amount of error. Table 4 also show significantly of coefficient and obtained parameters of measurement model of intrinsic motivation variable that show all the coefficients are significant. The scores of test which are greater than 1.96 or less than -1.96 indicate significantly of relationships ( Table 5).
Goodness of fit statistics like (chi-square =456.95), which compare to the degrees of freedom 194 is less than the number 3, which indicate very acceptable Goodness of fit. According to the achieved results, we observed that the Cronbach's alpha coefficient for sport motivation was 0.80 which indicates good reliability ( Table 2). Cronbach's alpha for the other dimension of sports motivation was shown at an acceptable level, except identified regulation and a motivation subscales that were relatively in weak level, and also with the removal of Question 1 of intrinsic motivation subscale and question 4 of a motivation subscale, Cronbach's alpha increased (Table 3). In study by Veskovic and Milanovic [11], Cronbach's alpha of identified regulation and

Variable
Sport motivation Omitted Question -

Conclusions
According to this issue that motivation is indicator of one of the most important variables in sport and also, the measurement instrument of motivation did not measure, at first, all kinds of explained motivation in self-determination theory in adequate and qualified way; Or presents weak factor structures; Mallett et al. developed Sports Motivation Scale-6 in 2007. The aim of the present study has been determining Validity and reliability of the measurement instrument of sport motivation in professional athlete of team sport of Iran and according to the results, itseems that spot motivation scale has been a valid and reliable scale in assessing the scale of the sport motivation for athletes. Moreover, the sport motivation scale model which used in the society of professional athletes in Iranian team sport was appropriate and all statements of sports motivation scale were significantly related to the mentioned variable. The overall result of this study is the Persian form of the sport motivation scale is equivalent to the English form, and it covers the basic concepts. For the future researches, it is recommended to use other statistical methods such as retest method for determining their liability of used tools in present study and try to compare the results of both studies.