Mathematics and Science Achievements Predicted by Self-Concept and Subject Value Among 8th Grade Saudi Students: Invariance Across Gender Maher M. Abu-Hilal Sultan Qaboos University Faisal A. Abdelfattah and Saleh A. Shumrani King Saud University Hamzah Dodeen United Arab Emirate University Adel S. Abduljabber King Saud University Herbert W. Marsh King Saud University and Oxford University The aims of this study were to evaluate the relationships among student’s self-perceptions, subject value, and achievement in mathematics and science in a single-sex educational milieu, and test whether the relationships were invariant across gender. The data for this study were obtained from the Third International Math and Science Study (TIMSS) 2007 database in which 4,099 eighth-grade Saudi students participated. The variables used in this study were mathe- matics and science self-concepts, subject value, and achievement in mathematics and science. The relationships among constructs were examined using structural equation modeling. The results revealed that the measurement and structural models were invariant across gender. Also, although the boys held more positive self-concepts (self-enhancing) about math and science, girls outperformed boys in both math and science (self-improving). The implication of the study is that intervention strategies should consider the conceptualization that self-concept and subject value are two distinct domain-specific constructs. Also, interventions may be differentially designed for boys and girls, especially in single-sex settings. However, more research should be conducted in which high-stake tests vs. low-stake tests like the TIMSS, are used as measures of achievement. Future research may study gender differences in self-concept, subject value, and achievement by using measurement models that provide more detailed information about measurement bias across gender groups. Keywords: TIMMS, math and science achievement, self-concept, attitudes, gender invariance Supplemental materials: http://dx.doi.org/10.1037/ipp0000022.supp Achievement behavior, self-perception (Heine, 2001), and self-evaluation (Becker et al., 2014) are best understood within a cultural context. Empirical research has indicated that “individuals evaluate themselves in culturally appropriate ways, deriving feelings of self- esteem particularly from those identity aspects that fulfill values prioritized by others in their Maher M. Abu-Hilal, Department of Psychology, Sultan Qaboos University; Faisal A. Abdelfattah and Saleh A. Shumrani, Department of Psychology, King Saud Univer- sity; Hamzah Dodeen, Department of Psychology, United Arab Emirate University; Adel S. Abduljabber, Depart- ment of Psychology, King Saud University; Herbert W. Marsh, Department of Psychology, King Saud University and Department of Psychology, Oxford University. This research was sponsored by The Excellence Re- search Center of Science and Mathematics Education, King Saud University. The authors would like to thank anonymous reviewers and the editor for their insightful comments on earlier versions of the paper. An earlier version of this paper was presented at the 6th Biennial International SELF Conference, 19 –22 July, 2011. Correspondence concerning this article should be ad- dressed to Maher M. Abu-Hilal, Department of Psy- chology, Sultan Qaboos University, PO Box 32, Al Khodh, Oman, PC 123. E-mail: mhilal@squ.edu .om This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. International Perspectives in Psychology: Research, Practice, Consultation © 2014 American Psychological Association 2014, Vol. 3, No. 4, 268 –283 2157-3883/14/$12.00 http://dx.doi.org/10.1037/ipp0000022 268