Concept mapping, i.e. the organisation of different items in a definite consistent structure, is a vital part of the terminology work preceding the creation of terminology records.

This conceptual analysis results in concept diagrams, i.e. schematic diagrams showing the attribute and the value of concepts within the law systems analysed as well as the relationships between them. They are graphic drawings representing the conceptual structure of specific domains and sub-domains containing the terms analysed in the database.

Due to the peculiarities of each law system, it was necessary to create separate concept maps for each language and subsequently to investigate their similarities and differences concerning single concepts as well as the relationships between them. This visual representation provides an overview of the way different law systems deal with Health and Safety at Work.

Principal ISO norms on terminology work were used to graphically represent the relationships between the concepts. However, ISO norms exclusively define "hierarchical" tree-like relationships, in particular generic relationships (x is a type of y) and whole-part relationships (x is a part of y). However, the majority of relationships between the concepts of the examined domain is more "flexible" — they need a free structure where no hierarchy between the concepts is established. Due to the nature of the examined relationships, "mixed" concept maps were used to combine the traditional tree-like shapes with a more flexible structure.

A main summary graph, named after the project domain "Health and Safety at Work", is provided to give an overview of the whole concept mapping. The domain is divided in different sub-domains used as organizing principle for the concept diagrams. Each concept map is named after the main conceptual area investigated.

The interaction between concept diagrams was thoroughly examined to make the consultation easier for the users. In particular, through the flags of the different States on the upper bar, you can directly access the equivalent concept map in the remaining three law systems. In addition, with the arrows in the upper right corner, you can "browse" the concept graphs within a single law system, go to the last chart available or return to the main summary graph.
In addition to the horizontal consultation of concept maps, a double navigation system is provided: from the terminology record (from the "Concept diagram" field) you can access the relevant concept charts and, vice versa, you can view terminology records clicking each active shape on the diagram. This correlation ensures both consistency and stronger interaction between the components of the knowledge base.

To make consultation easier and avoid a complex and arbitrary symbolic representation, some "satellites" or nodes were provided along the arrows linking the single shapes to make the semantic relationships between the concept more explicit. As far as practicable, these nodes contain the same words used to define the single concept in the termbase. There are two reasons for this choice — firstly, the linguistic consistency makes it easier for users to understand the concept diagrams; secondly, there is a clear matching between terminology records and concept maps. As consequence, the concept diagrams are not a simple translation of each other, but they show the peculiarities of each law system, including the use of language.