The disclosed embodiments relate to a system that facilitates performing searches based on qualitative search terms. During operation, the system receives a query that applies a qualitative search term to an attribute of data items in a set of data items. While executing the query, the system processes each data item in the set of data items by extracting an attribute value from the data item and then using a concept-mapping to determine a compatibility index for the attribute value, wherein the concept-mapping associates each attribute value with a numerical compatibility index that indicates a compatibility between the attribute value and the qualitative search term. Finally, the system uses the compatibility index as a factor in determining whether to include the data item in a set of query results.