South African hacker history South African hacker history A brief history of computer hacking in South Africa. Note: A distinction needs to be made between a "white hat" hacker who hacks out of intellectual curiosity, and a "black hat" hacker who has ulterior motives. In recent times there has been an attempt to restore the meaning of the term hacker, which is still associated with creating code, and its secondary meaning, which has become the stuff of Hollywood legend. The term "cracker" is a better description for those who break into secured system by exploiting computer vulnerabilities. Activists are trapped by BOSS agents who
Item-item collaborative filtering Earlier collaborative filtering systems based on rating similarity between users (known as user-user collaborative filtering) had several problems: Item-item models resolve these problems in systems that have more users than items. Item-item models use rating distributions "per item", not "per user". With more users than items, each item tends to have more ratings than each user, so an item's average rating usually doesn't change quickly. This leads to more stable rating distributions in the model, so the model doesn't have to be rebuilt as often. When users consume and then rate an item, that item's similar items are picked from