The Decompositional Semantics Initiative (Decomp) collects and models simple, commonsensical annotations of meaning inspired by linguistic theory.

Traditional semantic annotation frameworks generally define complex, often exclusive category systems that require highly trained annotators to build. And in spite of their high quality for the cases they are designed to handle, these frameworks can be brittle to deviations from prototypical instances of a category.

Decomp is founded on the idea that semantic annotation should rather take the form of many simple questions about words or phrases in context that are (i) easy for naive native speakers to answer, thus allowing annotations to be crowd-sourced; and (ii) more robust than traditional category systems, thus allowing coverage of non-prototypical instances.

Decomp has a sister project aimed at collecting type-level lexical and phrasal annotations: the MegaAttitude Project.