Shift of Bias without Operators

Just as the order defined by generality over concepts allows concept induction to be performed without generalisation/specialisation operators, so too the order defined by set inclusion over concept languages may allow the shift to better concept languages during learning to be performed without language shift operators. We are currently investigating this idea and in this paper we report first results. We present a framework for sided language shift adapted from Mitchell's version space strategy, and discuss its theoretical requirements and practical limitations. We illustrate the ordering-driven versus operatordriven strategy to language shift with a problem example (i.e., version-space induction over variable-factored conjunctive concept languages) to which our framework has been successfully applied.