This paper presents a new view of ExplanatiomBased Learning (EBL) of natural language parsing. Rather than employing EBL for specializing parsers by inferring new ones, this paper suggests employing EBL for learning how to reduce ambiguity only partially.We exemplify this by presenting a new EBL method that learns parsers that avoid spurious overgeneration, and we show how the same method can be used for reducing the sizes of stochastic: grammars learned from treebanks, e.g. (Bod, 1995, Charniak, 1996,