The Constant Concept in Graphical Representation: an analysis of stock price projections by engineering students

Abstract

This paper is the result of an exploratory initiative to identify previous knowledge, understanding, and intuitions of 47 engineering students about the stock price behavior of companies from different economic sectors. The activity, implemented at the beginning of the semester of Economics for an Engineering course, aimed to identify how students project and, above all, justify the behavior of stock prices using (or not) micro or macroeconomic elements. More precisely, using the theory of semiotic representation registers, this work is dedicated to the interpretation of a particularly curious phenomenon identified among the descriptions presented by students: the use of the word constant (and its derivations) to qualify the behavior of graphs that are in fact not constant in the literal and mathematical sense of the term. The results, when compared with the previous literature that identified the tendency of students to produce linear graphs, differ because they indicate something opposite, even due to the nature of the proposed activity. Students did not produce linear graphs that adhered to their textual descriptions, indicating difficulties in conceptualizing and coordinating distinct semiotic representation records. On the other hand, when the results are compared with studies that identified a tendency to simplify or smooth graphs, it was observed in the present study a tendency to simplify, flex or conceptual and semantic smoothing of the word constant.

Keywords:
Registers of Semiotic Representation; Graphic Registers; Textual Registers