Redaction critics assume an extreme skepticism toward the historicity of Jesus and the gospels, just as form critics do, which has been seen by some scholars as a bias. The process of redaction seeks the historical community of the final redactors of the gospels, though there are often no textual clues. Porter and Adams say the redactive method of finding the final editor's theology is flawed. In the New Testament, redaction critics attempt to discern the original author/evangelist's theology by focusing and relying upon the differences between the gospels, yet it is unclear whether every difference has theological meaning, how much meaning, or whether any given difference is a stylistic or even an accidental change. Further, it is not at all clear whether the difference was made by the evangelist, who could have used the already changed story when writing a gospel. The evangelist's theology more likely depends on what the gospels have in common as well as their differences. Harrington says, "over-theologizing, allegorizing, and psychologizing are the major pitfalls encountered" in redaction criticism.