In spite of its popularity, Keyword Search mode has not been standardized. While information professionals are quick to adapt to various presentations of Keyword Search mode, novice end-users often find Keyword Search confusing. This article compares Keyword Search mode in some major reference databases and calls for standardization.
Su, D. (2010). Standardization of Keyword Search Mode. Journal of Electronic Resources Librarianship, 22(1-2), 28-39.