Abstract:

Good graphs are extremely powerful tools for displaying large quantities of complex data. They help turn the realms of information available today into relevant knowledge, make the communication of important quantitative information easier, and are often used as effective decision support tools. Graphs are properly used only if they are clear, concise, and correct. Unfortunately, some graphs may mislead or deceive. Misleading graphs may be created intentionally to hinder the proper interpretation of data or accidentally due to misinterpretation of data, unfamiliarity with graphing software, or because data cannot be accurately conveyed.

In recent years the graphic communication is becoming an increasingly important form by which students and their teachers communicate in teaching and learning experiences. The ability to understand graphically presented information is usually called the graph literacy. In our paper we evaluated the level of graph literacy of students of University of Žilina. We constructed the test consisting of two parts: general graph literacy and graphical representation of differential calculus. The aim of our research was to test whether our students correctly understand the graphical information and what is the level of connection between the analytical description of function and its graphical representation. Finally, we proposed several means to improve graph literacy of students.

Keywords:

Misleading graphs, graph literacy, differential calculus.