He surveyed editions of medieval French texts that were produced with the stemmatic method, and found that textual critics tended overwhelmingly to produce trees divided into just two branches. He concluded that this outcome was unlikely to have occurred by chance, and that therefore, the method was tending to produce bipartite stemmas regardless of the actual history of the witnesses.
What was Joseph Bédier's main criticism of the stemmatic method?
critics tended overwhelmingly to produce trees divided into just two branches.