Score only works for searches with the searches endpoint, you are using the contents endpoint.
Thank you Jens for your response.
However, my concern is : Does the attribut score applies only for Ideas or all the contents (Documents, discussions, ...) ?
I'm currently working on search engine which retrieves results from Jive and some indexed documents in Elasticsearch. Furthermore, i'm trying to gather both of their search results in one set ordered by score. I'm aware that Jive uses a customized version of lucene search. I have attached an Image which clarifies my Idea