In linguistic semantics, a case role is any of the spatially-distinguished parts of a process.

In the sentence, "The dog ate food", the subject "dog" has the case role of "agent

Agent (grammar)

In linguistics, a grammatical agent is the cause or initiator of an event. Agent is the name of the thematic role...

" and the object "food" has the case role of "theme".

The meaningful case roles are dependent on the process. e.g.:

for process crime, case roles could be: perpetrator + victim

Crime

Crime is the breach of rules or laws for which some governing authority can ultimately prescribe a conviction...

 + evidence

Evidence (law)

The law of evidence encompasses the rules and legal principles that govern the proof of facts in a legal proceeding. These rules determine what evidence can be considered by the trier of fact in reaching its decision and, sometimes, the weight that may be given to that evidence...

 + modus operandi

Modus operandi

Modus operandi is a Latin phrase, approximately translated as "mode of operation". The term is used to describe someone's habits or manner of working, their method of operating or functioning...

;

for process burn, case roles could be: fuel

Fuel

Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...

, air, heat

Heat

In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...

The term has its origins in linguistic semantics, but is used in computerized natural language processing

Natural language processing

Natural language processing is a field of computer science and linguistics concerned with the interactions between computers and human languages; it began as a branch of artificial intelligence....

, where a software reasoning engine performs case role analysis to establish progressively more specialized case roles from speech. For example: 'subject', 'agent', 'mother', 'Fred's mother', is a logical progression that results from the phrase 'you gave birth to Fred.'.