1. A method of training a data profiler to monitor a quality of data extracted from a content source, the method comprising: receiving an acceptable data element for a first characteristic of data extracted from a first content source by a data extractor; identifying, from a plurality of constraint modules, a set of one or more constraint modules applicable to the first characteristic; adjusting, for each constraint module in the identified set of one or more constraint modules, parameters of the respective constraint module to accept the received acceptable data element; determining, for each constraint module in the identified set of one or more constraint modules, based on the adjustments, whether each respective constraint module is stable or non-stable; and generating a set of trusted constraint modules selected from the stable constraint modules, omitting the constraint modules determined as non-stable.