Branching identification key

A branching identification key is a presentation form of a single-access key where the structure of the decision tree is displayed graphically as a branching structure, involving lines between items.^[1] Depending on the number of branches at a single point, a branching key may be dichotomous or polytomous.

In a diagnostic key, the branching structure of the key should not be mistaken for a phylogenetic or cladistic branching pattern.

All single-access keys form a decision tree (or graph if reticulation exists), and thus all such keys have a branching structure. "Branching key" may therefore occasionally be used as a synonym for single-access key.

Examples of branching presentations

• http://www.warwickshire-sss.org.uk/subject/science/Biological_keys_v2.htm
• Figure 19.5 in ^[1]
• Page 8 in.^[2]

References

1. Winston, J. 1999. Describing Species. Columbia University Press.
2. The Natural History Museum 2000. Sorting creepy-crawlies. http://www.nhm.ac.uk/education/activities/school-activities/discovery-guides/assets/sorting.pdf