To leverage the large volume information buried in deep web, previous work has proposed techniques which include dark web understanding and dark web crawlers, and web samplers. For all these approaches, the ability to crawl deep web is a key challenge so the search paper Assessing relevance and trust of the deep web sources and results based on inter-source agreement.
In this, the problem of ranking database tuples for keyword search in databases has been addressed. The focus of these papers is on relevance assessment of tuples for keyword search in a single database. The problems of trust and importance are not considered. Improving web database search relevance by exploiting the search results from a surface web search engine. This paper considers the relevance assessment for search in a single database, and does not consider the trust problem. Further, the paper assumes the availability of high-quality web search results on the same topics as a reference (Raju & Subbarao, 2011, pp. 227-236).