The document discusses different levels of coupling between data mining (DM) systems and database/data warehouse (DB/DW) systems. It defines:
1) No coupling as DM systems operating independently without utilizing any DB/DW functions.
2) Loose coupling as DM systems fetching data from and storing results in DB/DW systems.
3) Semi-tight coupling as DM systems linking to and using efficient implementations of some DM functions within DB/DW systems.
4) Tight coupling as DM systems being fully integrated with and optimized based on the query processing and data structures of DB/DW systems.