Panna (right understanding) develops progessively in different stages of insight knowledge. When the first stage of insight knowledge arises there is no doubt about the difference between the characteristic of nama and the characteristic ofrupa. At a higher stage of insight the arising and faling away of nama and rupa, their impermanence, can be penetrated. in the course of development of insight a clearer understanding is gained of the three characteristics of conditioned realities, namely the characteristics of impermanence, dukkha, and non-self.