A French term, ‘terrain’ (terrain / ground / field) , used in social science and in natural science to designate elements of the lithosphere (e.g., ‘sedimentary terrains’) as well as the place, and by extension the subject,of research. For numerous researchers, ‘in the field’ activity represents one of the essential dimensions of their disciplinary method. In these disciplines, there has been a transfer from the lithologic, ‘terrestrial’, and thus a priori ‘geographical’ referent, toward the research subject itself, located in a particular place.

In the field of exploration, discoveries, or even conquests, direct presence on the ground and occupation of the ground are essential points in time for making the inventory of the territory or covering the ground with a grid, essential preliminaries to its cartography.
From these beginings the concept of ‘terrain’ was developed (terrain / ground / field), designating at the same time the research space, the mission, and the work of investigation in situ. In anthropology, field research occupies an essential place and constitutes a kind of rite of passage for the novice researcher (G. Condominas). It is research work par excellence. In geography, a quasi ignorance of the terrain in the modern period, dominated by by the geographer in his study compiling travel narratives, was replaced by a golden age of the terrain in the first half of the nineteenth century. Today, the term remains in use primarily among specialists of physical geography and of overseas geographies (cultural areas, development geography, etc). But whatever the social science, the notion of terrain is no longer merely a synonym for a faraway place, exoticism or a ‘different’ society. The term ‘terrain’ is actually used equally at the point when the work scale is delineated, when a survey is conducted or when the research process implies travel.

In a more or less implicit way, ‘terrain’ is often synonymous with the concrete, with direct contact with the reality of things (‘field worker’). It is the place where things are revealed to the eyes (‘field data books’, ‘field surveys’) as opposed to constructions, or to purely theoretical speculations generated from ‘laboratory’ work. Testing in the field is used in some sense as a principle of validation, of the emergence of truth: the expression ‘ground truthing’ is even used in remote sensing, in a scientific approach to which discovery in the field seems to add an extra degree of rationality. In classical geography, for which direct contact with and a visual approach to the study subject are essential, trips into the field are of vital importance for the geography student. The objective of this type of geography was to learn how to examine and to describe, according to an approach through landscapes.. The ‘terrain’ is the place where geographical knowledge takes form. For E. de Martonne, who, in 1905, conceived of the inter-university excursion, the field was considered a sort of common laboratory, a discussion forum for exchanging points of view. In order to represent the reality of the field , documentary supports such as topographical maps and aerial photographs (satellite images?) bring the assistance of this medium to the geographer’s relationship with the field, and play a supporting role for a number of conventional exercises.

In every period, the question of the mediation between the study object and the interpretation of the researcher has been raised. Whereas, with the approach of realism, the ‘terrain’ represents the place where hypotheses are confirmed, the particular relationship between the researcher and ‘his’ ‘terrain’ (empathy, objectivity, participating observation, militant intervention, etc.), and the frequent use of possessive adjectives and pronouns in the discourse about the research places, give rise to the thought that the ‘terrain’ may also serve as a mediator in revealing confrontations between distancing (alienation) and identity.