Dhyāna in Buddhism the Japanese Rinzai school, but it also occurs in other schools or branches of Zen depending on the teaching line. The Zen student's mastery of a given kōan is presented to the teacher in a private interview (referred to in Japanese as "dokusan" (独参), "daisan" (代参), or "sanzen" (参禅)). While there is no unique answer to a kōan, practitioners are expected to demonstrate their understanding of the kōan and of Zen through their responses. The teacher may approve or disapprove of the answer and guide the student in the right direction. The interaction with a Zen teacher is central in
Buddhism in Vietnam (, "Collection of Outstanding Figures of the Zen Garden") has been the dominant text used to legitimize Thiền lineages and history within Vietnam. However, Cuong Tu Nguyen's "Zen in Medieval Vietnam: A Study and Translation of the Thien Tap Anh" (1997) gives a critical review of how the text has been used to create a history of Zen Buddhism that is "fraught with discontinuity". Modern Buddhist practices are not reflective of a Thiền past; in Vietnam, common practices are more focused on ritual and devotion than the Thiền focus on meditation. Nonetheless, Vietnam is seeing a steady growth in Zen