Prior art

I will now identify the most relevant prior art for US patent 9218414 by examining its patent citations. Due to the nature of this request, a direct search of the USPTO database for citations isn't feasible through this interface. However, I can access information about US9218414 through Google Patents, which often includes citation data.

US Patent 9218414, titled "System, method, and user interface for a search engine based on multi-document summarization," was published on December 22, 2015, and has a priority date of February 6, 2007.

To identify the most relevant prior art, I will look for references that are explicitly cited within the patent document itself. I will focus on the "Prior art keywords" and "Other versions" sections provided in the patent information to guide my analysis.

The patent explicitly states that it claims priority benefit from U.S. patent application Ser. No. 12/023,014, filed on January 30, 2008, which in turn claims priority benefit from U.S. provisional application for patent Ser. No. 60/888,515, filed on February 6, 2007. U.S. Pat. No. 8,239,358 is also mentioned as being related to the 12/023,014 application. These are directly related applications within the same patent family and are crucial for understanding the patent's lineage but aren't "prior art" in the sense of anticipating its claims under 35 U.S.C. § 102. Rather, they establish the priority date.

Without direct access to the "References Cited" section of US9218414 via the provided tools, I cannot list all patent citations with their full details, descriptions, and specific claim anticipations. However, based on the description, the core innovation of US9218414 lies in combining search engine technology with multi-document summarization to produce a digest of relevant search results, including non-textual media, as the primary search output.

Therefore, the most relevant prior art would likely involve:

• Systems providing individual document summaries: The patent explicitly distinguishes itself from systems that "provide individual summaries of search results," stating that its innovation is in "multi-document summarization." Any prior art disclosing single-document summarization in a search context would be relevant for establishing the known state of the art before US9218414. Such prior art would potentially anticipate claims related to basic summarization functionality but not the multi-document aspect or the integration as the main search result.
• Search engines returning lists of documents/links: The patent describes existing search methods as generally returning "a large amount of Web pages that the user typically has to go through." Thus, any conventional search engine predating the priority date that returns a list of links or documents as its primary output would be considered prior art, particularly for claims relating to the initial search component. This would include essentially all widely used search engines at the time.
• Multi-document summarization techniques (generally known): The patent states, "Multi-document summarization systems are known to those skilled in the art." While not a specific patent, the general knowledge and existing algorithms for multi-document summarization would be prior art. Any publications or patents detailing such algorithms, especially those analyzing syntax, semantics, and extracting key concepts from multiple documents, would be highly relevant. These would potentially anticipate the summarization process itself, but not necessarily its integration as the primary output of a search engine or the specific user interface features.
• Question answering systems or knowledge bases: The patent also discusses alternative embodiments involving integration with "a question answering system" or a "knowledge base." Prior art in these areas that attempt to synthesize information from multiple sources to answer a user's query would be relevant, especially for claims related to generating a summary as an answer.

Without the specific list of "References Cited" from the patent document itself, it is impossible to provide the precise full citations, descriptions, and claims potentially anticipated for each piece of prior art. My analysis is based on the descriptions of the invention and the explicit distinctions made within the patent's own text.