Standard parameters for searching behaviour in search engines and their empirical evaluation

Search engines have become the most important medium for Internet users to find pages on the web. They help customers to decrease their information overload, and enhance the sales of commercial web sites in different ways. For these reasons, the exploration of and changes in (human) online searching behaviour has become a subject of particular importance. This paper will help search engine and web site administrators and developers to monitor online searching behaviour properly and to derive strategies from the information gained. We define standard parameters against which search engines can be measured and compared. These parameters also reflect the online searching behaviour of search engine users. Therefore, an overview of studies conducted in the last few years is given. Statistics used in different papers are compared to extract standard parameters for online searching behaviour. In the next step, search queries from four different search engines covering periods of between 10 and 13 months are compared using these parameters. Using an automatic process, we retrieved around 99% of all search queries from three different search engine live tickers. For the first time, different data sets over a long period are compared. We observe that some patterns stay stable in a number of different search engines, and shed light on patterns that shorter analyses could not adequately examine. Our observations do not support the assumption that web search has become more business driven. For this reason, we introduce the concept of evergreens in search queries. One implication is that search engines should simplify web search interfaces for users since Boolean operators and special search features are rarely used. We also present the evergreen topics in search queries.