1. OPERATIONAL INVARIANTS RELATED TO CHEMICAL REPRESENTATION: DYNAMICS ASPECTS OF THE CONCEPTUALIZATION Marco Antonio Bueno Filho 1, Carmen Fernandez 2, Liliana Marzorati 2 1 Universidade Federal do ABC - UFABC, Santo André, 09210-580, Brazil. 2 Chemistry Institute, University of São Paulo, São Paulo, C.P. 26077, Brazil. e-mail: marco.antonio@ufabc.edu.br In introductory organic chemistry courses, stereochemistry has been frequently mentioned as a source of difficulties mainly because it requires a clear visualization and mental manipulation of the molecular structures on space 1. However, been familiar with structural stereoviews is just one of the requisite skills for a proper learning of concepts of organic chemistry. In addition, it is also necessary to understand the conceptual content of the symbolical representations. This study investigates the processes of formal logical operations of the chemical action of representing and relate them to the conceptual content of thought. Barke, H.-D.; Engida, T.; Chemistry education: research and practice in europe, 2001, 2, 227-23. Fassnacht, C.; Woods, D.; 2008, Wisconsin Center for Education Research of University of Wisconsin-Madison. Verganud, G.; Human Development, 2009, 52, 83-94. Vergnaud, G.; Reserches en Didactique des Mathématiques, 1990, 23, 133-170. McNeill, D. Hand and Mind: what gestures reveal about thought. 1992, University of Chicago Press. Toulmin, S, The uses of argument,1958, Cambridge University Press. DimensionDefinitionCategory Conceptual Concepts and theorems implicits or explicits in the subject's actions. Theorem-in-action (TA) Concepts-in action (CA) Arguments Rules that determines the actions sequence of the student. (D) Fact, (J) Warrant, (B) Backing, (Q) Probably, (R) Rebuttal, (C) Conclusion Gestural Movements demanded by subjects in action, holders of meaning. (DE) Demonstrative, (BA) Beats, (CO) Cohesive, (ME) Metaphoric, (IC) Iconic. INTRODUCTION We analyzed data related to stereochemical problems solving gathered from 58 undergraduate students enrolled in Chemistry, Engineering and Pharmacy Courses. The recordings were made on video and transcribed with the help of the software Transana 2. In order to access the conceptual elements related to the action of the students, categories were defined based on Vergnaud’s Theory of Conceptual Fields 3,4, and focused on oral and gestural resources 5. The structure of the argument was articulated through the Toulmin´s conceptual content model 6. METHOD Figure 2 - Subject A27, MEI argumentation diagram SubjectMEIEIMESubjectMEIEIMESubjectMEIEIME A1A18XA47X A2XA19XA48X A3XA26XA49X A5XA27XA50X A6XA28XA51X A8XA29XA52X A9XA32XA53X A10XA33XA54X A11XA38XA55X A12XA39XA56X A13XA43XA57X A14XA44XA58X A15XA45X A17 X A46 X Figure 3 - Subject A39, ME argumentation diagram Table 2 - Invariants´s association in the selected participants Table 1 - Definitions adopted As a result, three operational invariants were proposed - the structural identity (I), equivalence (E) and free movement in space (M) - as conceptual elements capable of association during the action of the subject. This association represents three schemes, ME, MEI and EI, which account for significant differences in students’ proposals and conclusions. RESULTS AND DISCUSSION REFERENCES a. Represents the image you would see in the mirror. b. It would be possible to overlap what you drew the initial object? c. Suppose were molecules. Would be the same compound or different compounds ? Why? d. Explain using models. Figure 1 - The reflection's problem.