Internet search engines – fluctuations in document accessibility

Abstract

An empirical investigation of the consistency of retrieval through Internet search engines is reported. Thirteen engines are evaluated: AltaVista, EuroFerret, Excite, HotBot, InfoSeek, Lycos, MSN, NorthernLight, Snap, WebCrawler and three national Dutch engines: Ilse, Search.nl and Vindex. The focus is on a characteristics related to size: the degree of consistency to which an engine retrieves documents. Does an engine always present the same relevant documents that are, or were, available in its databases? We observed and identified three types of fluctuations in the result sets of several kinds of searches, many of them significant. These should be taken into account by users who apply an Internet search engine, for instance to retrieve as many relevant documents as possible, or to retrieve a document that was already found in a previous search, or to perform scientometric/bibliometric measurements. The fluctuations should also be considered as a complication of other research on the behaviour and performance of Internet search engines. In conclusion: in view of the increasing importance of the Internet as a publication/communication medium, the fluctuations in the result sets of Internet search engines can no longer be neglected.

Extracting accurate and complete results from search engines: Case study windows live

“…Subsequent research encompassed Google and tracked the coverage of a large set of Web sites, finding a pattern of stability but with occasional sudden changes (Thelwall, 2001). The research of Mettrop and Nieuwenhuysen (2001) also used a time series approach but used a set of controlled seed URLs in order to get more detailed information on search engine performance. They confirmed that search engines sometimes did not report a page even when it matched a query and was in their index (Mettrop & Nieuwenhuysen, 2001).…”

Google Scholar citations and Google Web/URL citations: A multi‐discipline exploratory analysis

“…Google has good coverage of HTML and non-HTML documents and supported the syntax necessary for extracting both Web and URL citations at the time of this study, as described below. Nevertheless, the results of Google do not represent the whole web [46], only the portion of the web that it has crawled and reports for user searches [47,48].…”

Fronteiras da Ciência da Informação

“…A preocupação com a estabilidade dos dados coletados por essas ferramentas foi debatida entre os pesquisadores em busca de possíveis soluções (BAR-ILAN, 1999;ROUSSEAU, 1999;METTROP;NIEUWENHUYSEN, 2001;VANTI, 2002;PAYNE;THELWALL, 2007). Independentemente desses questionamentos, os mecanismos de busca foram considerados como a principal fonte de dados para estudos webométricos.…”