document: Search engines and their public interfaces : which apis are the most synchronized ? Researchers of commercial search engines often collect datausing the application programming interface ( API ) or by `` scraping '' results from the web user interface ( WUI ) , butanecdotal evidence suggests the interfaces produce differentresults . We provide the first in-depth quantitative analysisof the results produced by the Google , MSN and Yahoo APIand WUI interfaces . After submitting a variety of queriesto the interfaces for 5 months , we found significant discrepanciesin several categories . Our findings suggest that theAPI indexes are not older , but they are probably smaller for Google and Yahoo . Researchers may use our findings tobetter understand the differences between the interfaces andchoose the best API for their particular types of queries .
doc_bio_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O