The Words attribute is not actually the number of occurrences of query words. It consists in ranking higher a document matching all of the words typed by the user rather than a document matching only some of them.
Example
Query: laser OR sword
- Words attribute is equal to 1 if the document contains only "laser" or only "sword".
- Words attribute is equal to 2 if the document contains both "laser" and "sword".
This attribute ranks documents in descending order.