@TechReport{Erbach:1993_2,
      AUTHOR = {Erbach, Gregor},
      TITLE = {Towards a Theory of Degrees of Grammaticality},
      YEAR = {1993},
      MONTH = {November},
      NUMBER = {34},
      ADDRESS = {Saarbrücken},
      TYPE = {CLAUS-Report},
      INSTITUTION = {Universität des Saarlandes},
      ABSTRACT = {This paper is concerned with ill-formed language. We distinguish two types of ill-formed language: string errors which can be explained by modifications to the string generated by the grammar, and grammar errors which can be explained by a modification of the grammar which generates the string. A chart-based method for dealing with string errors is presented. We discuss the adequacy of different grammatical formalisms for dealing with grammar errors, and show that context-free grammars are not expressive enough, but that constraint-based grammars are more suitable, if absolute and non-absolute constraints are distinguished. We augment non-absolute constraints in these grammars with probabilities. The relationship between the grammaticality of a string and its probability is discussed.}
}