Structuralism/ Behaviorism[EN]

In the 1940s and 1950s, the structural or descriptive, school of linguistics, with its advocates -Leonard Bloomfield, Edward Sapir, Charles Hockett, Charles Fries and others -prided itself in rigorous application of the scientific principle of observation of human languages. Only "publicly observable responses" could be subject to investigation. The linguist's task according to the structuralist was to describe human languages and to identify the structural characteristics of those languages. An important axiom of structural linguistics was that languages can differ from each other without limit," and that no preconceptions could apply to the field.

source: The Principles of Language Learning and Teaching.H Douglas Brown