Google, Yahoo! och Live Search
en evaluering av tre webbsöktjänster
The purpose of this Master?s thesis is to evaluate three general query-based web search engines. The search engines chosen are Google, Yahoo! and Live Search. The topics, which where transformed into twenty queries, are based on real users? information needs, taken from an ask-a-question service. For every search the first 10 hits in each of the three search engines were evaluated. The measures that have been used are precision and overlap. The queries were evaluated on a binary relevance scale with 0 or 1. Precision has been measured as average precision over 1-10 DCV levels for all 20 queries in the evaluation. It has also been measured as average precision in a query-by-query calculation over 10 DCV levels for each query and search engine. The number of duplicate links, dead links, mirror pages, relevant hits and irrelevant hits has also been recorded in the study for each search engine, for a comparison. Overlap was measured at two different DCVs, 1 and 5. Eventually the results show that Google had the best results regarding precision. It also had the highest number of relevant hits. Google and Yahoo! showed the highest overlap at DCV 1. At DCV 5 the greatest overlap was between Yahoo! and Live Search.