Column Type Annotation

Column type annotation (CTA) refers to the task of predicting the semantic type of a table column and is a subtask of Table Annotation. The labels that are usually used in a CTA problem are semantic types from vocabularies like DBpedia, Schema.org or WikiData. Some examples are: Book, Country, LocalBusiness etc.

CTA can be either treated as a multi-class classification problem where a column is annotated by only one semantic type or as multi-label classification problem where a column can be annotated using multiple semantic types.