Pew Research Center

Pew Research Center describes itself as a nonpartisan fact tank that informs the public about the issues, attitudes, and trends shaping the world. Its 2021 survey of religion in India is the only Research-Grade report in the CID corpus. The study interviewed nearly 30,000 adults face-to-face across India in 17 languages, with fully documented methodology, rigorous probability sampling, and published limitations. This is the benchmark for what survey research on India can look like when done well.