Anagnorisis
Aristotle lists the ways in which recognition can take place in a tragic plot.

Signs
The least imaginative method for bringing about a recognition, according to Aristotle, is through some identifying mark or sign. An example of this kind of anagnorisis is Euryklea's recognition of Odysseus by the scar on his thigh.

Contrived Revelations
Aristotle also criticizes strained devices that require that characters reveal their identities simply because a recognition must take place to advance the plot.

Memory
Events in the plot may awaken memories in one of the characters, as the songs of the harper in the Phaiakian court arose Odysseus's memories and bring about the revelation of his identity.

Reasoning
Sometimes characters figure out another's identity through logical analysis. Aristotle approves of this kind of anagnorisis; only anagnorisis arising naturally from the unfolding of the plot is superior to that brought about by reasoning.

Natural Outcomes of the Plot
The best kind of recognition scene is completely integrated into the action of the plot. The messenger arriving to tell Oedipus to stop worrying about the prophecy, for example, unwittingly brings about the revelation of Oedipus's real identity.