rationalism or empiricism ？

hello，everyone.
After some survey, I get some conclusion:
1. Knowledge graph is a concept made by google.
2. Knowledge graph is a kind of knowledge engineering.
3. Knowledge engineering has two components: knowledge base and inference engine.
4. Knowledge engineering has two schools of thought: rationalism  and empiricism.
5. Rationalism derive rule-based approach and empiricism derive statistic-based approach.
6.The rule-based approaches value the soundness and completeness of the inference engine and the statistic-based approach value the richness of the knowledge base.
7.The OWL is a kind of rule-based approach and the vector-based approach is a kind of statistic-based approach.
8.In the internet, the knowledge base is huge.It is always impossible to do a complex inference  on a huge knowledge base. 

My question is: In google, is the statistic-based approach  the main approach? Is the OWL used in google’s knowledge graph? Besides Google search engine， is there any other successful application of the knowledge graph? Besides knowledge graph, is there any other successful knowledge engineering in the industrial world？