[1][2][3] The term personal knowledge base was mentioned as early as the 1980s,[4][5][6][7] but the term came to prominence in the 2000s when it was described at length in publications by computer scientist Stephen Davies and colleagues,[1][2] who compared PKBs on a number of different dimensions, the most important of which is the data model that each PKB uses to organize knowledge.
[1]: 37–41 Non-electronic personal knowledge bases have probably existed in some form for centuries: Leonardo da Vinci's journals and notes are a famous example of the use of notebooks.
[11] Undoubtedly the most famous early formulation of an electronic PKB was Vannevar Bush's description of the "memex" in 1945.
[1][2][12] In a 1962 technical report, human–computer interaction pioneer Douglas Engelbart (who would later become famous for his 1968 "Mother of All Demos" that demonstrated almost all the fundamental elements of modern personal computing) described his use of edge-notched cards to partially model Bush's memex.
[13] In their 2005 paper, Davies and colleagues mentioned the following, among others, as examples of software applications that had been used to build PKBs using various data models and architectures:[1]