The Nyaya school of Hindu philosophy considers four valid means to correct knowledge: perception, inference, comparison and testimony of reliable sources. Perception is primary, and is based on five sensory inputs (eye, ear, touch, taste and smell). The other three methods depend on it, according to Nyaya school.
To verify the interconnection and maps above: [1] Jeaneane Fowler (2002), Perspectives of Reality: An Introduction to the Philosophy of Hinduism, Sussex Academic Press, ISBN 978-1898723943, page 134-146; [2] Karl Potter (2004), The Encyclopedia of Indian Philosophies: Indian metaphysics and epistemology, Volume 2, Motilal Banarsidass, ISBN 978-8120803091, pages 222-238; [3] Stephen Phillips (2014), Epistemology in Classical India: The Knowledge Sources of the Nyaya School, Routledge, ISBN 978-1138008816, Chapter 1
Epistemology in the Hindu text Nyaya sutras: Pratyaksha, Anumana, Upamana, Sabda

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Ms Sarah Welch