How to find similar content using SPARQL
Matching some specific properties
It sounds like you're asking for something along the lines of
select ?similarMovie ?genre ?director ?location ?actor where {
values ?movie { <http://.../TheMatrix> }
?genre ^:hasGenre ?movie, ?similarMovie .
?director ^:hasDirectory ?movie, ?similarMovie .
?location ^:hasLocation ?movie, ?similarMovie .
optional { ?actor ^:hasActor ?movie, ?similarMovie .
}
That uses the backwards path notation ^
and object lists to make it much shorter than:
select ?similarMovie ?genre ?director ?location ?actor where {
values ?movie { <http://.../TheMatrix> }
?movie :hasGenre ?genre .
?movie :hasDirector ?director .
?movie :hasLocation ?location .
?similarMovie :hasGenre ?genre .
?similarMovie :hasDirector ?director .
?similarMovie :hasLocation ?location .
optional {
?movie :hasActor ?actor .
?similarMovie :hasActor ?actor .
}
}
For instance, using DBpedia, we can get other films that have the same distributor and cinematographer as The Matrix:
select ?similar ?cinematographer ?distributor where {
values ?movie { dbpedia:The_Matrix }
?cinematographer ^dbpprop:cinematography ?movie, ?similar .
?distributor ^dbpprop:distributor ?movie, ?similar .
}
limit 10
SPARQL Results
The results are all within that same franchise; you get: The Matrix, The Matrix Reloaded, The Matrix Revolutions, The Matrix (franchise), and The Ultimate Matrix Collection.
Matching at least some number of properties
It's also possible to ask for things that have at least some number of properties in common. How many properties two things need to have in common before they should be considered similar is obviously subjective, will depend on the particular data, and will need some experimentation. For instance, we can ask for Films on DBpedia that have at least 35 properties in common with the Matrix with a query like this:
select ?similar where {
values ?movie { dbpedia:The_Matrix }
?similar ?p ?o ; a dbpedia-owl:Film .
?movie ?p ?o .
}
group by ?similar ?movie
having count(?p) > 35
SPARQL results
This gives 13 movies (including the Matrix and the other movies in the franchise):
- V for Vendetta (film)
- The Matrix
- The Postman (film)
- Executive Decision
- The Invasion (film)
- Demolition Man (film)
- The Matrix (franchise)
- The Matrix Reloaded
- Freejack
- Exit Wounds
- The Matrix Revolutions
- Outbreak (film)
- Speed Racer (film)
Using this kind of approach, you could even use the number of common properties as a measure of similarity. For instance:
select ?similar (count(?p) as ?similarity) where {
values ?movie { dbpedia:The_Matrix }
?similar ?p ?o ; a dbpedia-owl:Film .
?movie ?p ?o .
}
group by ?similar ?movie
having count(?p) > 35
order by desc(?similarity)
SPARQL results
The Matrix 206
The Matrix Revolutions 63
The Matrix Reloaded 60
The Matrix (franchise) 55
Demolition Man (film) 41
Speed Racer (film) 40
V for Vendetta (film) 38
The Invasion (film) 38
The Postman (film) 36
Executive Decision 36
Freejack 36
Exit Wounds 36
Outbreak (film) 36