Porpose: The current paper tried to present a structural model based on organizational silence prediction according to leadership style and organizational learning through the mediation of organizational commitment for the Islamic Azad University of Tehran.
Method: It is an applicable study using descriptive-correlation method. The research population consisted of all employees in the Islamic Azad university of Tehran in the academic year 2016-2017. Out of this population (8021), 367 participants were chosen based on the Krejcie and Morgan table using random cluster sampling. In order to gather data, the following questionnaire were applied: standardized organizational silence questionnaires, by Wacola and Boards (2005), Bass and Olive leadership style (1997), Marsick and Watkins organizational learning (1996), and Allen & Meyer organizational commitment (1990). Structural equation modeling was used to analyze the data.
Findings: The results showed that organizational silence can be predicted positively and meaningfully through transactional leadership style and transformational leadership style, organizational learning, organizational commitment and organizational justice, and negatively through non-intervention leadership style.
Conclusion: Organizational justice mediates between transformational and transactional leadership styles with organizational silence. Organizational justice does not mediate between the organizational learning and organizational silence. Organizational commitment, positively mediates the relationship between transactional leadership style and organizational silence, while mediating negatively between non-intervention leadership style and organizational silence.
Presenting the Structural Model of Organizational Silence based on Leadership Style and Organizational Learning with the Mediation of Organizational Commitment
 
Introduction: The current research was conducted to provide a structural model of organizational silence based on leadership style and organizational learning with the mediation of organizational commitment in the Islamic Azad University of Tehran.
Materials and methods: This research is practical, and in terms of the data collection method, was a descriptive correlation. The statistical population of this research included all the employees of the Islamic Azad University of Tehran in 2018-2019, of which 8021 people were selected using Krejcie and Morgan's Table by random cluster sampling. Vakola and Bouradas's (2005) organizational silence questionnaire was used to collect data. Its purpose is to examine the factors that cause organizational silence and it consists of 15 items and 3 components (top management's attitude towards silence (5 items), supervisor's attitude towards silence (5 items), and communication opportunities (5 items). The scale of this questionnaire is Likert type and its rating is between 1 and 5. The range of responses to the items is set as (completely disagree=1, disagree=2, somewhat agree=3, agree=4, and completely agree=5). In the aspect of top management's attitude towards silence, items 3, 4, and 5 were raised in reverse and their points were calculated opposite to the above points. In the research, the reliability correlation of this questionnaire was obtained using Cronbach's alpha method for the components of senior management's attitude towards silence and supervisor's attitude towards silence and communication opportunities equal to 0.609, 0.591, and 0.584 respectively. Salawati, Yarahamdi, and Seyed Hashemi (2013) confirmed the validity of this questionnaire with the help of the content validity method and by using exploratory and confirmatory factor analysis methods and the KMO index. Bass and Olive's (1997) multi-factor leadership style questionnaire, which aims to evaluate the factors and indicators of transformational leadership, exchange leadership, and non-interventional leadership, consists of 41 items and three components (transformational leadership (19 items), exchange leadership (17 items) and leadership non-intervention (5 items)). The scale of this questionnaire is of the Likert type and its scoring is between 1 and 5, the range of responses to the items is set as (completely disagree=1, disagree=2, somewhat agree=3, agree=4, and completely agree=5). In the current study, the reliability of this questionnaire was obtained through the internal consistency method using Cronbach's alpha for the components of transformational leadership, exchange leadership, and non-interventional leadership equivalent to 0.783, 0.762, and 0.619, respectively. Zahid Bablan (2014) confirmed the formal and content validity of the questionnaire after its translation based on the opinion of experts and obtained the simultaneous validity of the Bass and Olive leadership style questionnaire (1997) equal to 0.83. Also, for the validity of this questionnaire, Mughli (2013) conducted the standardization of the relevant test and confirmed its validity. Marzick and Watkins's organizational learning questionnaire (1996) aims to evaluate organizations in the dimensions of individual learning, team learning, and organizational learning and consists of 43 items and three components (individual learning (13 items), team learning (6 items), and organizational learning (24 items). The scale of this questionnaire is Likert and its scoring is between 1 and 6. he scale of response to the items is set as (very low=1, low=2, relatively low=3, relatively high=4, high=5, and very high=6). In the current study, the reliability correlation of this questionnaire was obtained using the internal consistency method by Cronbach's alpha for individual learning, team learning, and organizational learning components of 0.712, 0.630, and 0.771, respectively. Nadi and Sajjadian (1389) investigated and confirmed the concurrent validity of the questionnaire using the construct validity method through the confirmatory factor analysis method. Furthermore, the validity of the questionnaire was confirmed by subject and psychometric and management experts (content validity) and it was checked and confirmed by 5 people from a selected sample of the main population (face validity). The purpose of Allen and Meyer's (1990) Organizational Commitment Questionnaire was to investigate the level of commitment of employees to the organization and consists of 24 items and three components (emotional commitment (8 items), continuous commitment (8 items), normative commitment (8 items)). The scale of this questionnaire is of Likert type and its scoring is between 1 and 7. The range of responses to the items is set as (very disagree=1, somewhat disagree=2, slightly disagree=3, somewhat agree=4, slightly agree=5, somewhat agree=6, and strongly agree=7). It is worth mentioning that items number 4, 5, 6, 8, 9, 10, 15, 16, 17, 18, 19, 21, and 24 have a reverse scoring approach. In the present study, the reliability correlation of this questionnaire was obtained using the internal consistency method by Cronbach's alpha for the components of emotional commitment, continuous commitment, and normative commitment equal to 0.664, 0.659, and 0.575, respectively. Sabz-Alian and Zahedi-Asl (2013) used content validity to measure the validity of the questionnaire. According to calculating the opinions of 10 master's students in management and social sciences through the CVI formula, which was used to measure the validity of the content, the amount of validity obtained for this research was announced as 0.66. For data analysis, structural equation modeling was done using AMOS software. Validity and reliability were confirmed.
Findings: The results of this research indicated that organizational commitment, organizational learning, exchange, and transformational leadership style positively and significantly predicted organizational silence. Also, the non-interference leadership style negatively and significantly predicted organizational silence. Furthermore, organizational commitment mediated the relationship between organizational learning and organizational silence; organizational commitment positively mediated the relationship between transactional leadership style and organizational silence; also, the relationship between non-interventionist leadership style and organizational silence is negatively mediated.
Conclusion: The variables of organizational commitment, organizational learning, and leadership style (transactional, transformational, and intervention) can each have an impact on the variable of organizational silence according to cultural, economic, organizational, and managerial issues.