Semi-supervised Learning for Mixed-Type Data via Formal Concept Analysis

摘要

Only few machine learning methods; e.g., the decision tree-based classification method, can handle mixed-type data sets containing both of discrete (binary and nominal) and continuous (real-valued) variables and, moreover, no semi-supervised learning method can treat such data sets directly. Here we propose a novel semi-supervised learning method, called SELF (SEmi-supervised Learning via FCA), for mixed-type data sets using Formal Concept Analysis (FCA). SELF extracts a lattice structure via FCA together with discretizing continuous variables and learns classification rules using the structure effectively. Incomplete data sets including missing values can be handled directly in our method. We experimentally demonstrate competitive performance of SELF compared to other supervised and semi-supervised learning methods. Our contribution is not only giving a novel semi-supervised learning method, but also bridging two fields of conceptual analysis and knowledge discovery.