Examining Strategies Used by Pre-service Science Teachers in Stoichiometry Problems in Terms of Proportional Reasoning

Abstract

Stoichiometry problems are one of the best examples of problem solving in chemistry education. Proportional reasoning supports correct answers in stoichiometry problems. It is needed to examine how these problems are solved as well as the accuracy of solutions because of the importance and benefits of conceptual problem solving. This study utilizes the embedded multiple case study design. The stoichiometry problem solutions of 37 pre-service science teachers (PSTs) were examined based on three units of analysis; (i) whether pre-service teachers balanced the equations correctly or not, (ii) the accuracy of solutions, and (iii) strategies used to solve problems. More than half of the PSTs balanced the equations correctly but most of them did not interpret the integers in the equations appropriately. Participants were inclined to use algorithmic approach more than proportional reasoning. The accuracy of solutions and the frequency of algorithmic approach increased while the complexity of problems decreased. PSTs had difficulties in making sense of integers of chemical reactions, using intensive units such as density, and converting units. It is thought that PSTs prefer to use strategies that they learnt in their prior learning experiences. Within the context of findings, we suggest that PSTs should be supported conceptually about the meanings of integers and should be introduced using proportional reasoning in problem solving prior to algorithms.

Keywords

• Stoichiometry problems,proportional reasoning,pre-service science teachers

Fen Bilimleri Öğretmen Adaylarının Stokiyometri Problemlerinin Çözümünde Kullandıkları Stratejilerin Orantısal Akıl Yürütme Açısından İncelenmesi

Abstract

Orantısal akıl yürütmenin doğru sonuca ulaşmayı sağladığı stokiyometri problemleri kimya eğitiminde problem çözmenin en iyi örneklerinden biridir. Kavramsal problem çözmenin önemi ve faydaları göz önüne alınarak, stokiyometri problemlerine ilişkin çözümlerin doğruluğunun yanı sıra nasıl bir yaklaşımla çözüldüğünün de incelenmesi gerekmektedir. Bu amaçla araştırmada nitel araştırma yöntemlerinden bütüncül çoklu durum kullanılmıştır. Çalışmada, 37 fen bilgisi öğretmen adayının stokiyometri problemlerine ilişkin çözümleri (i) tepkimeleri doğru denkleştirilip denkleştirilmediği, (ii) çözümlerin doğruluğu ve (iii) problem çözümünde kullanılan stratejiler olmak üzere üç adımda incelenmiştir. Öğretmen adaylarının yarısından fazlasının tepkimeleri doğru denkleştirdiği ancak denkleştirilmiş tepkimelerdeki katsayıları doğru yorumlayamadığı görülmüştür. Öğretmen adayları algoritmik yaklaşımı orantısal muhakeme stratejilerinden daha fazla kullanmayı tercih etmiştir.  Soruların karmaşıklık düzeyi arttıkça öğretmen adaylarının problemleri doğru çözme ve algoritmik yaklaşımı kullanma oranları azalmıştır. Öğretmen adaylarının stokiyometri problemlerini çözerken tepkimelerdeki katsayıların belirttiği molar oranı tam olarak anlamlandıramadığı, tepkimeye giren maddelerden biri yoğunluk gibi intensif bir birim cinsinden verildiğinde çözüme ulaşamadıkları ve birimleri doğru dönüştüremedikleri gözlemlenmiştir. Öğretmen adayları stokiyometri problemlerini daha önceki derslerinde nasıl çözmeyi öğrenmiş iseler yine aynı şekilde çözmeyi tercih ettikleri düşünülmektedir. Bulgular çerçevesinde, kimyasal tepkime problemlerinden önce katsayıların ne anlama geldiği ile ilgili kavramsal desteğin sağlanması, problem çözümüne orantısal akıl yürütme stratejileri ile başlanarak bu desteğin işlemsel süreç ile pekiştirilmesi önerilmiştir.

Keywords

• Stokiyometri problemleri,orantısal akıl yürütme,fen bilimleri öğretmen adayları

References

1. Adigwe, J. C. (2013). Effect of mathematical reasoning skills on students’ achievement in chemical stoichiometry. Review of Education Institute of Education Journal, University of Nigeria Nsukka, 23(1), 1-22.
2. Agudelo-Valderrama, C., & Martínez, D. (2016). In pursuit of a connected way of knowing: The case of one mathematics teacher. International Journal of Science and Mathematics Education, 14(4), 719-737.
3. Akatugba, A. H., & Wallace, J. (1999). Sociocultural influences on physics students’ use of proportional reasoning in a non-western country. Journal of Research in Science Teaching, 36(3), 305-320.
4. Anderson, J. R. (1993). Rules of the mind. Hillsdale, NJ: Lawrence Erlbaum.
5. Aydın, A. (2011). Fen Bilgisi öğretmenliği öğrencilerinin bazı matematik kavramlarına yönelik hatalarının ve bilgi eksiklerinin tespit edilmesi. Balıkesir Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 13(1), 78-87.
6. Birinci Konur, K., & Pırasa, N. (2010). Sınıf öğretmenliği adaylarının mol kavramındaki ișlem becerilerinin belirlenmesi, Çukurova Üniversitesi Eğitim Fakültesi Dergisi, 3, 150-161.
7. BouJaoude, S., & Barakat, H. (2003). Students' problem solving strategies in stoichiometry and their relationships to conceptual understanding and learning approaches. Electronic Journal of Science Education, 7(3), 1-42.
8. Bowles, M. A. (2010). The think-aloud controversy in second language research. Routledge.

9. Case, J. M., & Fraser, D. M. (1999). An investigation into chemical engineering students’ understanding of the mole and the use of concrete activities to promote conceptual change. International Journal of Science Education, 21(12), 1237-1249.
10. Cramer, K., & Post, T. (1993). Proportional reasoning. The Mathematics Teacher, 86(5), 404-407.
11. Dahsah, C., & Coll, R. K. (2008). Thai grade 10 and 11 students’ understanding of stoichiometry and related concepts. International Journal of Science and Mathematics Education, 6, 573-600.
12. Daley, H., & Malley, R. F. (1988). Problems in chemistry (2nd Edition). New York: Marcel Dekker, Inc.
13. Dawkins, K. (2000, September). Analyzing teachers' conceptions of ratio and proportion in the context of mass/mole relationships. Paper presented at the meeting of The Association of Teacher Educators in Europe, Barcelona, Spain.
14. Desjardins, S. G. (2008). Disorder and chaos: Developing and teaching an interdisciplinary course on chemical dynamics. Journal of Chemical Education, 85(8), 1078-1082.
15. diSessa, A. A. (1988). Knowledge in pieces. In G. Forman and P. Pufall (Eds.) Constructivism in the computer age, (pp. 49-70). Hillsdale, NJ: Erlbaum.
16. Doka, M. G. (2010). Effective techniques for writing correct inorganic chemical formulae and equations in olayiwola. A. A. and Umoh, S. A. (eds). Effective Methods for teaching Inorganic Chemistry Science, Teachers Association of Nigeria: Ibadan.
17. Ericsson, K. A., & Simon, H. A. (1998). How to study thinking in everyday life: Contrasting think-aloud protocols with descriptions and explanations of thinking. Mind, Culture, and Activity, 5(3), 178-186.
18. Frazer, M. J., & Servant, D. (1986). Aspects of stoichiometry titration calculations. Education in Chemistry, 23(2), 54-56.
19. Furio, C., Azcona, R., & Guisasola, J. (2002). The learning and teaching of the concepts ‘amount of substance’ and ‘mole’: A review of the literature. Chemistry Education: Research and Practice in Europe, 3(3), 277-292.
20. Gabel, D. L., & Bunce, D. M. (1994). Research on problem solving. In D. Gabel (Ed.), Handbook of research on science teaching and learning, pp. 301-326. New York: Mac Millan.
21. Gulacar, O. (2007). An investigation of successful and unsuccessful students' problem solving in stoichiometry. Unpublished doctoral dissertation, Western Michigan University, Michigan.
22. Gulacar, O., Overton, T. L., Bowman, C. R., & Fynewever, H. (2013). A novel code system for revealing sources of students' difficulties with stoichiometry. Chemistry Education Research and Practice, 14(4), 507-515.
23. Hafsah, T., Rosnani, H., Zurida, I., Kamaruzaman, J., & Yin, K. Y. (2014). The influence of students’ concept of mole, problem representation ability and mathematical ability on stoichiometry problem solving. Scottish Journal of Arts, Social Sciences And Siıentific Studies, 3, 3-21.
24. Harel, G., Behr, M., Post, T., & Lesh, R. (1992). The block task: Comparative analysis of the task with other proportional tasks and qualitative reasoning skills of seventh-grade children in solving tasks. Cognition and Instruction, 9(1), 45-96.
25. Heller, P. M., Ahlgren, A., Post, T., Behr, M., & Lesh, R. (1989). Proportional reasoning: The effect of two context variables, rate type, and problem setting. Journal of Research in Science Teaching, 26(3), 205-220.
26. Hoban, R. (2011). Mathematical transfer by chemistry undergraduate students. Dublin: Dublin City University.
27. Huddle, P. A., & Pillay, A. E. (1996). An in‐depth study of misconceptions in stoichiometry and chemical equilibrium at a South African university. Journal of Research in Science Teaching: The Official Journal of the National Association for Research in Science Teaching, 33(1), 65-77.
28. Hwang, B. (1994). A study of proportional reasoning and self-regulation instruction on students’ conceptual change in conceptions of solution. Paper presented at the National Association of Research in Science Teaching, Anaheim, CA.
29. Inhelder, B., & Piaget, J. (1958). The growth of logical thinking from childhood to adolescence. New York: Basic Books.
30. Johnstone, A. H. (2000). Teaching of chemistry-logical or psychological? Chemistry education: research and practice in Europe, 1(1), 9-15.
31. Kimberlin, S., & Yezierski, E. (2016). Effectiveness of inquiry-based lessons using particulate level models to develop high school students’ understanding of conceptual stoichiometry. Journal of Chemical Education. 93, 1002-1009.
32. Lesh, R., Post, T., & Northern, M.B. (1988). Proportional reasoning. In J. Heibert, & M. Behr (Eds.) Number concepts and operations in the middle grades (pp.93-118). Reston, VA: Lawrence Erlbaum & National Council of Teachers of Mathematics.
33. Merriam, S. B. (2009). Qualitative research: A guide to design and implementation (Revised and expanded from qualitative research and case study application in education). San Francisco: Jossey-Bass.
34. Miles, M., & Huberman, A. M. (1994). Qualitative data analysis. Beverly Hills, California: Sage.
35. Mitchell, A., & Lawson, A. E. (1988). Predicting genetics achievement in non-science majors college biology. Journal of Research in Science Teaching, 25(1), 23-37.
36. Musa, U. (2009). Teaching the mole concept using a conceptual change method at college level. Education, 129(4), 683-691.
37. Nakhleh, M., & Mitchell, R. (1993). Concept learning versus problem solving: There is a difference. Journal of Chemical Education, 70(3), 190-192.
38. National Research Council (NRC). (2000). Inquiry and the national science education standards: A guide for teaching and learning. Washington, DC: National Academy of Sciences.
39. Niess, M. L. (2005). Preparing teachers to teach science and mathematics with technology: Developing a technology pedagogical content knowledge. Teaching and Teacher Education, 21(5), 509-523.
40. Nurrenbern, S. C., & Pickering, M. (1987). Concept learning versus problem solving: Is there a difference? Journal of Chemical Education, 64(6), 508-510.
41. Nyachwaya, J. M., Warfa, A. M., Roehrig, G. H., & Schneiderd, J. L. (2014). College chemistry students’ use of memorized algorithms in chemical reactions. Chemistry Education Research and Practice, 15, 81-93.
42. Pascarella, A. (2002). CAPA (Computer-assisted personalized assignments) in a large university setting. Doctoral Dissertation, University of Colorado, Boulder, CO. (T 2002 P2614).
43. Plano Clark, V. L., & Creswell, J. W. (2015). Understanding research: A consumer’s guide. Upper Saddle River, NJ: Pearson Education.
44. Ramful, A., & Narod, F. B. (2014). Proportional reasoning in the learning of chemistry: levels of complexity. Mathematics Education Research Journal, 26(1), 25-46.
45. Schmidt, H. J. (1997). An alternate path to stoichiometric problem solving. Research in Science Education, 27, 237-249.
46. Schmidt, H. J., & Jigneus, C. (2003). Students’ strategies in solving algorithmic stoichiometry problems. Chemistry Education: Research and Practice, 4(3), 305-317.
47. Shadreck, M., & Enunuwe, O. C. (2018). Recurrent difficulties: Stoichiometry problem-solving. African Journal of Educational Studies in Mathematics and Sciences, 14, 25-31.
48. Shuell, T. (1990). Phases of meaningful learning. Review of Educational Research, 60, 531-547.
49. Staver, J. K., & Jacks, T. (1988). The influence of cognitive reasoning level, cognitive restructuring ability, disembedding ability, working memory capacity and prior knowledge on students’ performance on balancing equations by inspection. Journal of Research in Science Teaching, 25(9), 763 – 775.
50. Tingle, J. B., & Good, R. (1990). Effects of cooperative grouping on stoichiometric problem solving in high school chemistry. Journal of Research in Science Teaching, 27(7), 671-683.
51. Wagner, E. (2001). A study comparing the efficacy of a mole ratio flow chart to dimensional analysis for teaching reaction stoichiometry. School Science and Mathematics, 101(1), 10-22.
52. Ward, C., & Herron, J. (1980). Helping students understand formal chemical concepts. Journal of Research in Science Teaching, 17(5), 387-400.
53. Wheeler, A., & Kass, H. (1977). Proportional reasoning in introductory high school chemistry. Cincinnati, OH: National Association for Research in Science Teaching.
54. Yarroch, W. L. (1985). Student understanding of chemical equation balancing. Journal of Research in Science Teaching, 22, 449-459.
55. Yin, R. K. (2003). Case study research: Design and method (3rd Edition). Thousand Oaks, London: Sage.