Project : axis
Section: Scientific Foundations
Keywords : case-based reasoning, experience management, reuse of past experiences, indexing, sequential patterns, user behaviour, use of an information system indexing.
Case-Based Reasoning (CBR) It is a problem solving paradigm based on the reuse by analogy of past experiences, called ``cases''. In order to be found, a case is generally indexed according to certain relevant and discriminating characteristics, called ``indices''; these indices determine in which situation (or context) a case can be re-used.
Case-Based Reasoning  usually breaks up into four principal phases :
a << retrieve >> phase for cases having similarities (i.e. similar indices) with the current problem,
a << re-use >> phase where a solution to the current problem is built, based on cases identified in the previous phase,
a << revise >> phase where the solution may be refined with an evaluation process,
a << retain >> phase, that updates the elements of the reasoning by taking into account the experiment which has been just carried out and which could thus be used for future reasoning.
Difficult problems in CBR are related to: definition and representation of a case, organization of the database containing the cases, various used indexing methods and definition of "good" similarities measurements for the case search, link research-adaptation link of case (the best case being the most easily adaptable case), definition of an adaptation strategy starting with the found case(s), training of new indices, etc.
We pursue the evaluation of our results in CBR, in particular the indexing model by behavioral situation, the object-oriented framework CBR*Tools and toolbox Broadway*Tools. Moreover, we study sessions indexing techniques and search algorithms of items sub-sequential patterns for the on-line and off-line analysis of the Web users usage.