“…Both these concepts were reformalized (the former named n-feedback learning, and the latter named n-memory learning) and thoroughly studied and discussed in [CJLZ99]. Motivation for these sorts of learnability models, as discussed in [CJLZ99], comes from the rapidly developing field of knowledge discovery in databases, which includes, in particular, data mining, knowledge extraction, information discovery, data pattern processing, information harvesting, etc. Many of these tasks represent interactive incremental iterative processes (cf., e.g., [BA96] and [FPSS96]), working on huge data sets, finding regularities, and verifying them on small samples of the overall data.…”