Neutral tools for unbiased information or evil, greedy manipulators? An evaluation and comparison of search results by three web-based search engines.

The purpose of this thesis is to evaluate three web-based search engines and compare the 10 first retrieved documents. We used the search engines Google, Yahoo! and Exalead. The evaluation is based upon 20 topics with strong polarized opinions and these have been derived from Swedish media and every day life. From these topics we have constructed the 20 queries used for searching. The 10 first documents are each placed in four different categories, For, Against, Neutral or Irrelevant. For and Against are opposed to each other regarding different opinions in the 20 topics. The purpose of this is to get a picture of the different topics, seen through the three search engines. Does one of the categories weigh more heavily than the other, represented in the 10 first documents? If this is the case, does the same category weigh more heavily in all three search engines, or how do they deviate from each other? The results showed that one of the categories, in most of the topics, weighs more heavily than the opposed category. The opposed category is in some cases not represented at all in the 10 first documents. In some of the topics, the same category weighs over in all three search engines, but in more than half of the topics the different search engines deviate from each other regarding the opposed categories.Uppsatsnivå: