"Pratyakṣa" (प्रत्यक्ष) means perception. It is of two types in Hindu texts: external and internal. External perception is described as that arising from the interaction of five senses and worldly objects, while internal perception is described by this school as that of inner sense, the mind. The ancient and medieval Indian texts identify four requirements for correct perception: "Indriyarthasannikarsa" (direct experience by one's sensory organ(s) with the object, whatever is being studied), "Avyapadesya" (non-verbal; correct perception is not through hearsay, according to ancient Indian scholars, where one's sensory organ relies on accepting or rejecting someone else's perception), "Avyabhicara" (does not wander; correct perception does not change, nor is it the result of deception because one's sensory organ or means of observation is drifting, defective, suspect) and "Vyavasayatmaka" (definite; correct perception excludes judgments of doubt, either because of one's failure to observe all the details, or because one is mixing inference with observation and observing what one wants to observe, or not observing what one does not want to observe). Some ancient scholars proposed "unusual perception" as "pramana" and called it internal perception, a proposal contested by other Indian scholars. The internal perception concepts included "pratibha" (intuition), "samanyalaksanapratyaksa" (a form of induction from perceived specifics to a universal), and "jnanalaksanapratyaksa" (a form of perception of prior processes and previous states of a 'topic of study' by observing its current state). Further, some schools of Hinduism considered and refined rules of accepting uncertain knowledge from "Pratyakṣa-pranama", so as to contrast "nirnaya" (definite judgment, conclusion) from "anadhyavasaya" (indefinite judgment).