This two-part study was designed (1) to determine differences in the costs of searching BRS After Dark (BRS AD) and Knowledge Index (KI) generally and across ten selected databases, and (2) to determine whether there is a difference in the citations retrieved when the same search is conducted on the same database in both systems. Study methodology involved conducting a total of 40 searches on topics chosen from patron inquiries and currently popular research paper topics, including 4 searches conducted in each of 5 databases available on both BRS AD and KI. Databases searched included Agricola, CAB (Commonwealth Agricultural Bureau), Medlars, NTIS (National Technical Information Service), Inspec, Psycinfo, Legal Resource Index, ABI Inform, National Newspaper Index, and ERIC (Educational Resources Information Center). Study results indicate that KI was generally less expensive than BRS AD when an average of 50 to 60 citations were printed and for those databases in BRS AD which have citation charges of more than three cents. In addition, results for a search conducted in the same database in both BRS AD and KI were usually not identical, especially if truncation was used, with more citations generally being retrieved in KI. (KM)