In this paper we present an onto-semiotic macroscopic analysis of the measures of dispersion: range, interquartile range, average deviation, variance, standard deviation and coefficient of variation by following the theoretical framework of the Theory of Semiotic Functions. This research has been carried out with a sample of textbooks from the most representative publishers used by Spanish second-cycle Secondary students of 15 and 16 years of age. The paper finishes by presenting several useful conclusions for the planning of the teaching process and for the research on the issue.