Hmm, don't have the training series here at the office today...
Are you familiar with table occurrences? Understanding what they are and how they control the database functions can be a key element to figuring out how an ERD matches up to the relationship graph--which is very similar to but not quite the same thing as an ERD.
You should be able to spot the join tables by the fact that they have two foreign key fields from two of the main tables in the system. Given the way table occurrences work, you may see the same such join table represented by more than "box" in manage | database | relationshps.
For more on table occurrences: Tutorial: What are Table Occurrences?
Thanks! I'm attempting to work through that. I really appreciate your article on TOs. Very helpful.
I know how to "talk" myself through an ERD (a teacher can teach many classes... a class has many students...), but I don't know how to "talk" myself through the FM relationship graph, which is why I think I'm struggling. The relationship graph also puts crow's feet in places where I don't expect them, or at least not where they were on my ERD. But, I feel a shimmer of greater understanding each time I think about it!
Thanks again for your help.
You may want to play with this demo file on many to many relationships: http://www.4shared.com/file/dZ0bjclw/ManyToManywDemoWExtras.html
And the "crows feet" in a FileMaker relationship graph tell you that a "many" relationship is possible on that end of the line, it does not tell you that you actually have a "many" relationship in terms of your data. If you define a unique values validation or an auto-entered serial number on the key field, the crows feet will disappear as a "many" on that end then becomes impossible.