master detail question

[tupac_rd]

Hi Gurus,

When creating a master detail relationship between 2 queries in a report, when should we create the relationship between the master query and the paramater value versus the relationship from the master to detail query. I was looking in the pdf and all I could find was

Use parameters when you want to filter values at a lower level in the detail query.

I could not figure out much. Please help me explain which is the best practice or in what scenarios we would use parameters or the data items in the detail query..

Thanks
dd