M. Jiménez-Castro, P. Arteaga, M.M. Gea, C. Batanero

University of Granada (SPAIN)
Statistical graphs are essential tools in communicating information in many different areas as well as in the media and consequently graphical competence is a main goal in school curricula in many countries. This is the case of the primary school curricula in Costa Rica that I recommend that children are requested to collect and record data to answer statistical questions about themselves and their environment, using bar charts, tables and pictograms, as well as to read and interpret these representations since the 1st grade. This goal can only be achieved with a correct teaching of the topic and the use of adequate textbooks.

Research analysing different content in textbooks is increasing today, since these books are a main didactical tool for teachers and students, and constitute an intermediate stage between the official curricular guidelines and the teaching implemented in the classroom. Consequently, we intended to analyse the way in which statistical graphs are presented in textbooks oriented to 1rst to 6th grades of basic education. In order to achieve this aim we performed a content analysis of all the activities (n=167) related to statistical graphs in two books series (grades 1rst to 6th) which are most widely used in Costa Rica.

Following ideas by Kosslyn, we consider statistical graphs as a resource that can be used with different purposes: a) Analysis; when the main goal is using the graph to identify or discover many features that are hidden in the unorganised data set; b) Communication, when the graph is used to transmit information about the data and its relationships in an efficient way; and c) Construction; in traditional teaching, an additional purpose is providing procedures to help students learn how to build a correct graph,

The results of the analysis proved that the main goal of graphs in the textbooks (40,7%) was analysis, followed by communication (36.5%) with only 18% graphs oriented only to learn how to build the graph. This distribution was not uniform in the two series of textbooks analysed, one of which only included 42,3% of communicative purposes, while the other only 25,0%.

There were also variation between the different grades with communication purpose concentrate in first and second degrees (75,0% y 59,1%), while in third year the most frequent purpose is construction (42,3%) and analysis predominates in the upper levels with more than 53% of activities. These results are useful for teachers who should take into account the relevance of context in statistics education and select adequate purposes when introducing their students to statistical graphs.