What is this probability tree model called?

news.cuhk.edu.hk · science forum beginner Joined: 22 Jun 2006 Posts: 9

Dear all,

I am trying to find the expected depth of an unbalanced tree (I have also
posted the problem a bit earlier). My friend refers me to look for a
probability tree model that is used to model a family tree. However, all he
remembers is that the model is related to birth-death process, but not
exactly the name of the model. He said that the model has the following
characteristics:

1. There is one ancestor for the family which is the root of the tree.
2. A node in the tree can give birth to 0 to N children (i.e., a random
variable).
3. When a node has 0 offsprings, it is the leaf node of the tree.

He said that this process can be used to analyze an unbalanced tree and the
expected depth can be easily found. Has anyone heard about this model? If
so, what is the name of it?

Thanks very much in advance.

Regards,

Patrick

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