Abstract Despite widespread use of Internet search engines, the online catalogue is still the main pathway to the collection of a particular library. The use of Internet search engines does, however, have implications for user expectations around the online catalogue, and search strategies when using the online catalogue. There is much research on online catalogue use that predates search engine use, and there is a need for more up-to-date research, particularly on the use of online catalogues in public libraries. This paper reports on an analysis of transaction logs of end users of the online catalogue of a large public library in Australia, the State Library of Victoria. It compares searches over four years, taking into account the search settings and search strategies and looking at search success, including the reasons for search failure. The paper also introduces the concept of abandonment rates to online catalogue search, defining a metric that adds to the useful information that can be determined from transaction logs. The paper uses the findings as the basis for its concluding recommendations for how public library users can be assisted to find what they are looking for on the library catalogue. A new context for OPAC use: the rise of search engines Online Public Access Catalogues (OPACs) first appeared in the 1970s (Hancock-Beaulieu & Borgman, 1996) gradually replacing the card catalogue. With the development of computer networks such as Telnet, users were able to access the catalogue remotely at a time of their choosing. Since then, OPACs have developed from single colour text screens that can be connected to remotely via Telnet, through to graphical user interfaces that can be accessed over the Internet. In the 1980s and 1990s, a vast amount of research was conducted on OPAC use. This has necessitated the periodic publication of review articles. Large and Beheshti (1997), for example, review more than seventy pieces of research on OPAC use published between 1990 and 1996, while Tenopir (2003) summarises more than 200 pieces of research on this topic published between 1995 and 2003. Although fairly recent, most of this research was undertaken in a technological context very different from now. For example the review of the literature in Bates (2003) relies on studies conducted before the mid 1990s, a time when few people had experience with using the Internet, and before the widespread use of Internet search engines. Markey (2007) describes the 1980s as the golden age of the online catalogue because library users depended on it almost exclusively for finding information on the topics that interested them (n.p.). In 1995, Internet search engines were known to only a small minority with access to the Internet. By contrast, in the month of April 2008, Google handled 5.1 billion queries in the US alone (Google Milestones, 2008). Search engines such as Google enable users to find highly relevant web sites by simply typing a few relevant words into a text box. Research conducted since the rise of search engine use suggests that people use the principle of least effort in their information seeking (Bates, 2003), favouring convenience (Tenopir, 2003) and ease of use (OCLC, 2005) when choosing amongst electronic information sources. The OPAC is convenient in that it is possible for users with a connection to the Internet to access the catalogue at any time, from any place. Even so, much research shows that people start their information searches with a search engine, and in particular with Google (see Markey, 2007 for a summary). Although there are many search engines available, Google is by far the most used. In 2008, Google's market share was almost 90% in the UK (Hitwise UK, 2008) and Australia (Hitwise Australia, 2008), 80% in Europe (Comscore, 2008) and more than 70% in the United States (Google nears 72 percent of U.S searches in November 2008, 2008). Users of search engines include searchers who are looking for information on the Internet as well as searchers wanting to find information contained in books. …