An Empirical Study on the “Usage of Not” in Real-World JSON Schema Documents

We study the usage of negation in JSON Schema data modeling. Negation is a logical operator rarely present type systems and schema description languages, since it complicates decision problems: many software tools, but also formal frameworks for working with Schema, do not fully support negation. This motivates us to whether actually used practice, which aims, could—in principle—be replaced by simpler operators. have collected large corpus 80k open source documents from GitHub. perform systematic analysis, quantify patterns negation, qualitatively analyze schemas. show that indeed used, albeit infrequently, following stable set patterns.