In this article, we intend to show how useful Exploratory Spatial Data Analysis is in improving spatial data usability. We first outlined a general framework about usability using conceptual modelling, including Data, Users and Methodologies. We then defined keywords into classes and their relations. A central ternary relation is enhanced to describe usability. In the second section, we present ESDA with its fundamental basics: i.e. robustness and way(s) to handle data and related graphic tools. We also described the software package ARPEGE'. Through a concrete example, we demonstrate and discuss its relevance for exploratory spatial data analysis and usability.