2. A method for data enrichment, the method comprising: measuring, by an attribute relevance module that is executed by at least one hardware processor, relevance of an attribute to a data object to be enriched, the data object including the attribute including one of a known and an unknown value, wherein the relevance of the attribute includes a determination of a unique association of the attribute with the data object, and a determination of a discriminative property of the attribute with respect to instances of the data object based on evaluation of an entropy of a predetermined number of past values of the attribute; determining, by an output value confidence module that is executed by the at least one hardware processor, a confidence of a source based on utility of an output value of the source used for enrichment of the data object, the output value representing at least one of the known and unknown values of the attribute; determining, by the at least one hardware processor, assignment of the unknown value to the attribute by using the measured relevance of the attribute and the determined confidence of the source; and determining, by a source utility and adaptation module that is executed by the at least one hardware processor, utility of the source for enrichment of the data object by determining a confidence of input values provided to the source.
14. The method of claim 2 , further comprising: selecting, by a source selection module that is executed by the at least one hardware processor, the source for enrichment of the data object from a plurality of sources by determining that the selected source can provide a value for the attribute.