It needs a labelled space that defines the relevant concepts to be identified (see change of base manual) and assessed. It also needs a model text or "golden text" that serves as the standard reference for comparison (see "Golden text" in the document on the main GallitoAPI files).

Once these components are ready, the task consists in evaluating the presence/absence of these concepts by comparison to their presence/absence in the standard text. It gives also an index of in-topic/out-topic