Absolutely. Tight coupling between data set instance and function that manipulates this data seems to be the current definition of object-orientation (as oppose

Absolutely. Tight coupling between data set instance and function that manipulates this data seems to be the current definition of object-orientation (as opposed to something more philosophical like "living entities communicating together", which is a bit vague IMHO). Rather than having one big memory chunk, and one big function chunk (like the old DATA DIVISION and PROCEDURE DIVISION of cobol), you divide thoses into smaller data+procedure bits that idealy map to existing concepts from your domain. That seems like a much more effective way of seeing the thing. Although once you start adding parallelism and asynchronous communication, you do probably end-up in something closer to the Kay definition.