case study
noun [ C ] uk/ˈkeɪs ˌstʌd.i/ us/ˈkeɪs ˌstʌd.i/
（尤指为说明一般原则而作的）个案研究
a detailed account giving information about the development of a person, group, or thing, especially in order to show general principles
This is an interesting psychiatric case study of a child with extreme behavioural difficulties. 这是一份很有意思的精神病个案研究，研究对象是一个有严重行为障碍的小孩。