亲身 (qīnshēn) means doing something oneself or in person, used with actions (亲身去, go in person). It differs from 切身 (qièshēn), which means directly concerning one's own interests (切身利益), and from 第一手 (dìyīshǒu), which refers to information from the original source. Unlike 个人 (gèrén), which is a noun modifying nouns (个人看法), 亲身 focuses on personal involvement.