This paper investigates the composition of search engine results pages. We define what elements the most
popular web search engines use on their results pages (e.g., organic results, advertisements, shortcuts) and to
which degree they are used for popular vs. rare queries. Therefore, we send 500 queries of both types to the
major search engines Google, Yahoo, Live.com and Ask. We count how often the different elements are used by
the individual engines. In total, our study is based on 42,758 elements. Findings include that search engines use
quite different approaches to results pages composition and therefore, the user gets to see quite different results
sets depending on the search engine and search query used. Organic results still play the major role in the results
pages, but different shortcuts are of some importance, too. Regarding the frequency of certain host within the
results sets, we find that all search engines show Wikipedia results quite often, while other hosts shown depend
on the search engine used. Both Google and Yahoo prefer results from their own offerings (such as YouTube or
Yahoo Answers). Since we used the .com interfaces of the search engines, results may not be valid for other
country-specific interfaces