In situation theory, situation semantics (pioneered by Jon Barwise and John Perry in the early 1980s)[1] attempts to provide a solid theoretical foundation for reasoning about common-sense and real world situations, typically in the context of theoretical linguistics, theoretical philosophy, or applied natural language processing, Situations, unlike worlds, are not complete in the sense that every proposition or its negation holds in a world.
The original theory of Situations and Attitudes soon ran into foundational difficulties.
[3] Barwise and Perry's system was a top-down approach which foundered on practical issues which were early identified by Angelika Kratzer and others.
She subsequently developed a considerable body of theory bottom-up by addressing a variety of issues in the areas of context dependency in discourse and the syntax–semantics interface.
[4] Because of its practical nature and ongoing development this body of work "with possible situations as parts of possible worlds, now has much more influence than Barwise and Perry’s ideas".