Are Norvig's comments on the "I before E except before C." really vaild? Why would one use a corpus for analysis of the rule, and not a dictionary? It appears t

Are Norvig's comments on the "I before E except before C." really vaild? Why would one use a corpus for analysis of the rule, and not a dictionary? It appears to me that "CIE" (P(CIE) = 0.0014) is more common than "CEI" (P(CEI) = 0.0005) because the words that contain the "exception" "CIE" are used more frequently in the corpus than the words that follow the rule "CEI". Once you know the limited number of exceptions (in the dictionary sense) the rule appears to preserve its relevance.