Position:
2013-present, Assistant Professor of Mathematics Education
2011-2013, Rutgers University, Postdoctoral Research Associate

Education:
2011, Columbia University, Ph.D. in Mathematics Education
2005, New York University, M.S. in Mathematics
2003, Boston University, Dual degree program in B.A. in Economics and Mathematics and M.A. in Economics, Magna Cum Laude

Selected publications:
20. Tjoe, H. (2020). Are some languages more mathematically preferred for counting purposes? In M. Inprasitha, N. Changsri, & N. Boonsena. (Eds.), Proceedings of the 44th Conference of the International Group for the Psychology of Mathematics Education (Interim Vol., pp. 603-611). Khon Kaen, Thailand: PME. (pdf) 19. Tjoe, H. (2020). Problems in algebra for teachers [Review of Problems in Algebra for Teachers, by A. Karp & J. Viro]. Teachers College Record. (pdf) 18. Tjoe, H. (2019). "Looking back" to solve differently: Familiarity, fluency, and flexibility. In P. Liljedahl, & M. Santos-Trigo. (Eds.), Mathematical Problem Solving ICME-13 Monographs (pp. 3-20). New York, NY: Springer-Verlag. (pdf) 17. Tjoe, H. (2017). The relationship between language complexity and mathematics performance. In B. Kaur, W. K. Ho, T. L. Toh, & B. H. Choy. (Eds.), Proceedings of the 41st Conference of the International Group for the Psychology of Mathematics Education (Vol. 4, pp. 273-280). Singapore, Singapore: PME. (pdf) 16. de la Torre, J., Carmona, G., Kieftenbeld, V., Tjoe, H., & Lima, C. (2016). Diagnostic classification models and mathematics education research: Opportunities and challenges. In A. Izsak, J. T. Remillard, & J. Templin. (Eds.), Psychometric methods in mathematics education: Opportunities, challenges, and interdisciplinary collaborations (pp. 53-71). Journal for Research in Mathematics Education Monograph Series No. 15. Reston, VA: NCTM. (pdf) 15. Tjoe, H. (2016). Aesthetics in school mathematics: A potential model and a possible lesson. The Mathematics Enthusiast, 13(3), 279-302. (pdf) 14. Tjoe, H. (2016). When is a problem really solved? Differences in the pursuit of mathematical aesthetics. In C. Csikos, A. Rausch, & J. Szitanyi. (Eds.), Proceedings of the 40th Conference of the International Group for the Psychology of Mathematics Education (Vol. 4, pp. 275-282). Szeged, Hungary: PME. (pdf) 13. Tjoe, H. (2015). Giftedness and aesthetics: Perspectives of expert mathematicians and mathematically gifted students. Gifted Child Quarterly, 59(3), 165-176. (pdf) 12. Tjoe, H. (2014). When understanding evokes appreciation: The effect of mathematics content knowledge on aesthetic predisposition. In C. Nicol, S. Oesterle, P. Liljedahl, & D. Allan. (Eds.), Proceedings of the 38th Conference of the International Group for the Psychology of Mathematics Education (Vol. 5, pp. 249-256). Vancouver, BC: PME. (pdf) 11. Tjoe, H., & de la Torre, J. (2014). On recognizing proportionality: Does the ability to solve missing value proportional problems presuppose the conception of proportional reasoning? Journal of Mathematical Behavior, 33(1), 1-7. (pdf) 10. Tjoe, H., & de la Torre, J. (2014). The identification and validation process of proportional reasoning attributes: An application of a cognitive diagnosis modeling framework. Mathematics Education Research Journal, 26(2), 237-255. (pdf) 9. de la Torre, J., Tjoe, H., Rhoads, K., & Lam, D. (2013). Conceptual and theoretical issues in proportional reasoning. International Journal for Studies in Mathematics Education, 6(1), 21-38. (pdf) 8. Incikabi, L., & Tjoe, H. (2013). A comparative analysis of ratio and proportion problems in Turkish and the U.S. middle school mathematics textbooks. Journal of Kirsehir Education Faculty, 14(1), 1-15. (pdf) 7. Tjoe, H., & de la Torre, J. (2013). Designing cognitively-based proportional reasoning problems as an application of modern psychological measurement models. Journal of Mathematics Education, 6(2), 17-26. (pdf) 6. Incikabi, L., Ozgelen, S., & Tjoe, H. (2012). A comparative analysis of numbers and biology content domains between Turkey and the USA. International Journal of Environmental and Science Education, 7(4), 523-536. (pdf) 5. Incikabi, L., & Tjoe, H. (2012). Comparing Turkish and American middle school mathematics textbooks: A content analysis. In T. Y. Tso (Ed.), Proceedings of the 36th Conference of the International Group for the Psychology of Mathematics Education (Vol. 1, pp. 244). Taipei, Taiwan: PME. (pdf) 4. Tjoe, H., & de la Torre, J. (2012). Evolution of proportional reasoning problems. In T. Y. Tso (Ed.), Proceedings of the 36th Conference of the International Group for the Psychology of Mathematics Education (Vol. 1, pp. 274). Taipei, Taiwan: PME. (pdf) 3. Tjoe, H., & de la Torre, J. (2012). Proportional reasoning problems: Current state and a possible future direction. In S. J. Cho (Ed.), Proceedings of the 12th International Congress on Mathematics Education (Vol. 1, pp. 6741-6750). Seoul, Korea: ICME. (pdf) 2. Tjoe, H. (2009). Multiples of positive integers and the pigeonhole principle. New York State Mathematics Teachers Journal, 59(2), 64-65. (pdf) 1. Tjoe, H. (2008). Building number sense: A rational number point of view. New York State Mathematics Teachers Journal, 58(3), 91-93. (pdf)

Editoral board member:
1. Electronic Journal of Mathematics and Technology (here)

Manuscript reviewer:
1. Asia-Pacific Education Researcher
2. Education as Change: Journal of Curriculum Research
3. International Journal of Quantitative Research in Education
4. Journal of Mathematical Behavior
5. Journal of Mathematics Education at Teachers College
6. Journal of Mathematics Teachers Education
7. Mathematics Teaching in the Middle School

Proposal reviewer:
1. American Educational Research Association: Division C (Learning and Instruction) Section 1c (Mathematics)
2. American Educational Research Association: SIG-Research on Giftedness, Creativity and Talent
3. American Educational Research Association: SIG-Research in Mathematics Education
4. Association of Mathematics Teachers Educators
5. National Association for Gifted Children
6. National Council of Teachers of Mathematics Research Conference
7. North American Chapter of the International Group for the Psychology of Mathematics Education