A-ha! I understand that I was not following what you recommended. When I mean manually, I mean that I can accomplish my problem by doing it only manually, but it takes a long time to do. Many apologies.
However, I still cannot achieve the task to hand as you have instructed:
Households -< Individuals -< Results >- Studies
Then you could start at a record in Studies and perform Go to Related Records [ from Households; Show related only; Match current record ] as step 1, and Go to Related Records [ from Individuals; Show related only; Match found set ] as step 2.
My current structure is:
Households --- Results
Fields within Households are: household number, individual number
Fields within Results are: individual number, results
The individual number in the 2 tables are the same and linked.
Thus I can search for positive test results in the Results table e.g. 20 out of 1000 tests, and use GTRR to give me the corresponding list in the Household table (as you listed in step 1), but I do not know how to show related records to allow me to see all the people who live in the same household (as these 20 people). I can do this manually, by control-clicking on the household number then clicking "Extend found set", but it takes a while.
Thanks again
Aikiko