V-structure: Difference between revisions

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The middle node in a v-structure is called a [[collider]]. (?)
The middle node in a v-structure is called a [[collider]]. (?)


Some authors seem to distinguish between a v-structure and an immoral v-structure. In this case, "v-structure" seems to only mean that there is a collision, and the "immoral" means the parents are not directly connected.<ref>Su-In Lee. [https://courses.cs.washington.edu/courses/cse515/11sp/class2-bayesnet.pdf "Bayesian Network Representation"]. University of Washington CSE 515, Statistical Methods, Spring 2011. p. 14 (slide 27). March 30, 2011. Retrieved September 21, 2018.</ref>
Some authors seem to distinguish between a v-structure and an immoral v-structure. In this case, "v-structure" seems to only mean that there is a collision, and the "immoral" means the parents are not directly connected.<ref>Su-In Lee. [https://courses.cs.washington.edu/courses/cse515/11sp/class2-bayesnet.pdf "Bayesian Network Representation"]. University of Washington CSE 515, Statistical Methods, Spring 2011. p. 14 (slide 27). March 30, 2011. Retrieved September 21, 2018.</ref><ref>Dave Essary. [https://people.cs.pitt.edu/~milos/courses/cs3710/Lectures/Class4.pdf "Bayesian Networks Representation"]. p. 15. Retrieved September 21, 2018.</ref>


==Terminology==
==Terminology==

Revision as of 00:34, 22 September 2018

In graphical models, a v-structure is a set of three nodes in a graph such that there are two converging arrows and the tails of the arrows are not connected by an arrow.[1][2] For example, X→Z←Y is a v-structure.

The middle node in a v-structure is called a collider. (?)

Some authors seem to distinguish between a v-structure and an immoral v-structure. In this case, "v-structure" seems to only mean that there is a collision, and the "immoral" means the parents are not directly connected.[3][4]

Terminology

why is this thing called a v-structure? because it looks like a letter V if the two parents are drawn above the common child?

References

  1. ↑ Judea Pearl. Causality. p. 19.
  2. ↑ "Bayesian networks". Retrieved September 21, 2018.
  3. ↑ Su-In Lee. "Bayesian Network Representation". University of Washington CSE 515, Statistical Methods, Spring 2011. p. 14 (slide 27). March 30, 2011. Retrieved September 21, 2018.
  4. ↑ Dave Essary. "Bayesian Networks Representation". p. 15. Retrieved September 21, 2018.