... We report results of an ongoing project to reconcile the heterogeneous indexing (keywords, index terms, and subject headings) applied to the existing ADS records. ... We describe the apprehension of this evidence through the use a spreading activation network. ... We applied the spreading activation model to investigate connections between two different subject vocabularies employed in ADS: Astrophysical Journal keywords (ApJ) and terms assigned to documents from the NASA Thesaurus (STI) 1 . ...