The research on graph exploration has revolved around three main pillars: keyword graph queries, exploratory graph analysis, and refinement of query results.
Exploratory methods have been proposed as a mean to extract knowledge from relational data without knowing what to search (Idreos et al. 2015). Graph exploration has been introduced to perform exploratory analyses on graph-shaped data (Mottin and Müller 2017). Graph exploration aims at mitigating the access to the data to the user, even if such user is a novice.
Algorithms for graph exploration assume the user is not able to completely specify the object of interest with a structured query like a SPARQL (see chapter “Graph Query Languages”), but rather expresses the need with a simpler, more ambiguous language.
This asymmetry between the rigidity of structured queries and ambiguity of the user has inspired the study of approximate, flexible, and example-based methods.