عنوان مقاله [English]
The purpose of this study was to examine the causal relationship between motivational variables and academic performance in science, mediated by conceptual understanding in male and female students of the eighth grade. The sample was recruited from all of eighth grade students in Darab city, Iran. The research method was correlational. The data gathered through the three questionnaires: the modified version of Harter's (1980, 1981) scale, Attitude Survey Questionnaire, and the researcher-made conceptual understanding of Science. In the descriptive section, the mean, standard deviation and correlation coefficient were used and in the inferential section, structural equation modeling was used. The results showed that all relationships between variables, except the extrinsic motivation for conceptual understanding were significant. Results also indicated that all indirect hypotheses, except the indirect relation of extrinsic motivation to the academic performance in science mediated by conceptual understanding were confirmed.
 Kayamanesh, A., & Meraji, S. (2011). The role of self-concept of science, attitude towards science on the academic performance of science in students of the eighth grade of Iran and Sweden based on the data of TIMSS 2007. Modern Educational Approaches, 6(14), 23-40. [In Persian]
 ShekaryKashani, Z., Damavani, M., & KaramiGhazafi, A. (2010). The effect of mastering learning method on the attitude, performance and inner motivation of high school girl students in learning the concepts of chemistry. New Thoughts of Education, 6(2), 155-172. [In Persian]
 Saif, A. (2017). New Educational Psychology. (11nd ed.).Tehran: Doran Publication.
 BaniAsadi, A., & Pourshafei, H. (2012). The role of motivation and academic self-efficacy and study approaches in mathematical development of high school students in experimental and math sciences in high school in the city of Qaen. New Thoughts of Education, 8 (4), 81-102. [In Persian]
 5. MusaviNasab, M. (2009). Motivation and learning. Islam and Educational Research. 1 ( 1), 107-130. [In Persian].
 Hosseinpour, M., Hasanzadeh, R., & Maddah, M. (2009). Investigating the relationship between interest in the field of study and academic achievement: in the curriculum of third year students in the workshops of the MahmoodAbad School of Mazandaran in the academic year of 2008-2009. Development School Counseling, 20, 4-12. [In Persian].
 Sikhwari, T.D. (2014). A Study of the Relationship between Motivation, Self-concept and Academic Achievement of Students at a University in Limpopo Province, South Africa. International Journal of Educational Sciences, 6 (1), 19-25.
 Oriahi, C. (2009). Influence of Motivation on Students’ Academic Performance. The Social Sciences, 4 (1), 30-36.
 Yousefi, A., Ghasemi, Gh., & Firouznia, S. (2009). The Relationship between Academic Motivation and Academic Achievement of Medical Students of Isfahan University of Medical Sciences. Iranian Journal of Medical Education, 9 (1), 79-85. [In Persian].
 Tella, A. (2007). The Impact of Motivation on Student’s Academic Achievement and Learning Outcomes in Mathematics among Secondary School Students in Nigeria. Eurasia Journal of Mathematics, Science & Technology Education, 3 (2), 149-156.
 Bahrani, M. (2005). Study of academic motivation among high school students in Fars province and related factors. Journal of Social Sciences and Humanities, 22 (4), 104-115. [In Persian].
 Hasanzadeh, R., & MehdiNejadGorji, G. (2014). Theories of Motivation in Education. Tehran: Ravan Publication.
 Sheikholeslami, R., & Rzavieh, A. (2005). The prediction of creativity of students at Shiraz University with regard to the variables of external motivation, internal motivation and gender. Journal of Social Sciences and Humanities University of Shiraz, 22 (4), 94-103. [In Persian].
 Nasri, S., Teimouri, R., & HamidiMajlj, M. (2013). Family Relationship Effect Modeling Affecting the Educational Motivation of High School Students in Tehran. Research in School Learning, 1 (3), 39-49. [In Persian].
 Hassanzadeh, R. (2012). The relationship between motivation (internal-external), control source (internal-external) and student's academic achievement. Educational Innovations, 1 (2), 107-121. [In Persian].
 Areepattamannil, S. (2014). Relationship between Academic Motivation and Mathematics Achievement among Indian Adolescents in Canada and India. The Journal of General Psychology, 141(3), 247–262.
 Qamari, M. (2013). Relationship between social capital and internal motivation with academic achievement of high school students in Karaj. Quarterly Journal of Education and Evaluation, 22, 45-58. [In Persian].
 Lepper, M.R., HenderlongCorpus, J., & Iyengar, S.S. (2005). Intrinsic and Extrinsic Motivational Orientations in the Classroom: Age Differences and Academic Correlates. Journal of Educational Psychology, 97 (2), 184-196.
 Bahrani, M. (2009). The validity and reliability of Hartre's academic motivation scale. Psychological Studies Faculty of Education Sciences and Psychology, 5 (1), 51-72. [In Persian].
 Moravati, Z., ShehniYialagh, M., Mehrabizadeh, M., & KiyanpourQahfarhi, F. (2009). The causal relationship between perceived constructive learning environment and math performance by mediating the goal orientation orientation, homework value, attitude toward mathematics and mathematical self-efficacy in high school boy students in Ahwaz. Journal of Psychological Achievements (Educational Sciences and Psychology). 4, (1), 16-21. [In Persian].
 Saberitabar, M. (2014). The relationship between mental health and attitudes toward mathematics and self-mediation in learning. (Unpublished master’s thesis). Shahid Rajaee University, Tehran.
 Karimi, Y. (2014). Attitude and Attitude Change. Tehran: Virayesh Publication.
 Soltani, A., ArbabiSirjo, A., DehghaniKhuzani, A. & Rezaei, M. (2011). The Attitude of Secondary School Students of Isfahan City toward the Science and Technology of School Science and the Environment. Research in Curriculum Planning, 8 (30), 73-83. [In Persian].
 Serįn, O & Mohammadzadeh, B. (2008). The Relationship between Primary School Students’ Attitudes towards Science and Their Science Achievement (Sampling: Izmir). Journal of Educational Sciences, 3 (2), 68-75.
 Pahlavan Sadiq, A., & Farzad, V. (2009). The Performance of Iranian Students' Science in the TIMSS 2003 According to Individual and Family Variables. Research in Curriculum Planning, 23 (21), 1-24. [In Persian].
 26. Budé, L. M. (2007). On the improvement of students' conceptual understanding in statistics education. (Unpublished doctoral dissertation). Maastricht University.
 Moran, R. K., & Keeley, P. (2015). Teaching for Conceptual Understanding in Science. United States of America: National Science Teachers Association.
 Kim, M., & Song, J. (2010). A Confirmatory Structural Equation Model of Achievement Estimated by Dichotomous Attitudes, Interest, and Conceptual Understanding. Eurasia Journal of Mathematics, Science & Technology Education, 6(4),271-285.