Next / Previous / Contents / TCC Help System / NM Tech homepage

6. Analysis notes

The overall structure of this catalog relates three entities:

  1. Each photo may depict one or more forms of bird.

  2. A form refers to all the photos that use a specific English name.

  3. The external taxonomy system places each English name into a specific biological taxon.

Here is an entity-relationship diagram (ERD) for these three entities. If you are not familiar with ERD notation, see the Wikipedia article on entity-relationship models.

The taxon object has a relationship to itself: a taxon may or may not have a parent, and it may have zero or more children. In short, taxon objects are structured as a tree.

Taxa have a one-to-many relationship to forms: a taxon may contain photos for only one form, or for more than one.

Photos have a many-to-many relationship with forms. A single photo may depict more than one kind of bird; and the catalog may contain zero or more photos of a kind of bird.