In this paper, we describe a formal constraint mechanism, which we label Conceptual Constraint Variables (CCVs), introduced to restrict surface patterns during automated text analysis with the objective of increasing precision in the representation of informational contents. We briefly present, and exemplify, the various types of CCVs applicable to the English texts of our corpora, and show how these constraints allow us to resolve some of the problems inherent to surface pattern recognition, more specifically, those related to the resolution of conceptual or syntactic ambiguities introduced by the most frequent English prepositions.