Search Result Merging and Ranking Strategies in Meta-Search Engines: A Survey

MetaSearch is utilizing multiple other search systems to perform simultaneous search. A MetaSearch Engine (MSE) is a search system that enables MetaSearch. To perform a MetaSearch, user query is sent to multiple search engines; once the search results returned, they are received by the MSE, then merged into a single ranked list and the ranked list is presented to the user. When a query is submitted to a MSE, decisions are made with respect to the underlying search engines to be used, what modifications will be made to the query and how to score the results. These decisions are typically made by considering only the user’s keyword query, neglecting the larger information need. The cornerstone of their technology is their rank aggregation method. In other words, Result merging is a key component in a MSE. The effectiveness of a MSE is closely related to the result merging algorithm it employs. In this paper, we want to investigate a variety of result merging methods based on a wide range of available information about the retrieved results, from their local ranks, their titles and snippets, to the full documents of these results.