1. A method for extracting attributes from input text, comprising: using regular expression matching to match tokens within the input text to attributes; generating data that indicates attribute extraction determinations made by the regular expression matching; feeding the data into a trained machine learning mechanism that produces predictions of accuracy for the attribute extraction determinations made by the regular expression matching; and producing filtered results by filtering from the attribute extraction determinations those attribute extraction determinations that were predicted to have a likelihood of accuracy that falls below a particular threshold.