SemEx
SemEx is a Semantic Query Editor Extension for VMTS. With SemEx one can build queries targeting semantic datasets by building a graph in a specialized visual graph editor. SemEx is powered by the DSL management capabilities of VMTS.
Features
- web-based visual query editor with real-time collaboration
- textual query generation (currently: SPARQL)
- executing textual query on semantic datastore enpoint (currently: Wikidata SPARQL Endpoint)
Case Study
We modeled query tasks of different complexity levels. Complexity categories are from paper of Soylu et al. The targeted semantic dataset is english Wikidata.
Query #1
Complexity: short linear = maximum length of chain of entities is less than 3
Task: Find the names of all the companies that distribute a movie titled "Titanic".

Query #2
Complexity: long linear = maximum length of chain of entities is at least 3
Task: Find the names of all the people who acted in a movie set in the 1990s and distributed by a company located in Hungary.

Query #3
Complexity: short with branching = multiple, connecting chains, maximum length of chain of entities is less than 3
Task: Find the names of all people who directed a science fiction movie and also played in a movie titled "1941".

Query #4
Complexity: long with branching = multiple, connecting chains, maximum length of chain of entities is at least 3
Task: Find the titles of all the movies that are distributed by a company founded by a person born in Hungary and directed by a person born in Los Angeles.

Query #5
Complexity: short with branching and Type III cycle = multiple, connecting chains, maximum length of chain of entities is less than 3 and with at least two variable nodes with the same type
Task: Find the names of all the people who directed a science fiction movie and acted in a movie distributed by a company founded by a person born in Budapest.

Query #6
Complexity: long with branching and Type III cycle = multiple, connecting chains, maximum length of chain of entities is at least 3 and with at least two variable nodes with the same type
Task: Find the names of all the people that directed a science fiction movie and had a role in a film that has an actor with a given name "George" who was born in the European continent and plays in a progressive rock band.

Contributors
- Dániel Palatinszky
- Veronika Kovács