A widely used device for the determination and representation of text meaning, based on the organisation of information primarily round verbs, or actions, by case roles, e.g. Agent, Instrument, Location. Case frames are ordinarily microstructures oriented towards linguistic units like sentences, as opposed to the knowledge-oriented macro-structures of frames <77>. Though reference to Fillmore’s linguistically-motivated ideas is conventional, there is great variation in the treatment of every aspect of case frames, e.g. their relation to features of the surface text (is the sentence subject the Agent?), their number (ten or thirty?), their status (obligatory or optional?), the constraints on their fillers (is the Agent HUMAN?). etc. Conceptual dependency <36>, for example, uses a small number of deep cases.