People have found outside references (like nodes "Helpful article about Bayesian Networks" and "Reference for How Bayesian Networks work") that could help clarify concepts that were discussed in "The Book of Why"

Pearl goes into great detail about the development and usage of Bayesian networks. The structure of nodes allows easier access to previously discussed topics and concepts that were incorporated into this concept. In addition, it can be helpful to have nodes that summarize larger concepts, like "Relation between Bayesian Networks and Causal Diagrams" and "From objectivity to subjectivity."