  In this paper we study the phase transitions of different types of Random
Boolean networks. These differ in their updating scheme: synchronous,
semi-synchronous, or asynchronous, and deterministic or non-deterministic. It
has been shown that the statistical properties of Random Boolean networks
change considerable according to the updating scheme. We study with computer
simulations sensitivity to initial conditions as a measure of order/chaos. We
find that independently of their updating scheme, all network types have very
similar phase transitions, namely when the average number of connections of
nodes is between one and three. This critical value depends more on the size of
the network than on the updating scheme.
