Content area
Full Text
Introduction
In the era of digital libraries, bibliographic and full-text databases have become common spaces for information resources searching and discovering, providing functionality and ease of use that are superior to printed products (Burke, 2001). The World Wide Web has introduced many advantages for databases and library searching tools as well. One of the main advantages of this environment is that it integrates many information resources and makes them available for searching from one location. Some of these resources are available on the surface web for public users and are able to be reached without any authentication requirements, while others, especially bibliographic databases, require user authentication to enable access to the deep web, which hide, most of the time, behind web scripts (Liu et al. , 2012).
Each one of these databases has a unique interface and searching capabilities. Searching different databases requires a good understanding, on the users' part, of the coverage and searching capabilities of each database, along with a perception of the area of interest and how to fully use the database's capabilities. Additionally, when switching databases, there is the difficulty of moving from one interface to the other. These difficulties have made the searching process tedious and time-consuming, rather than easy and time-saving. These challenges often push library users to complain about the complexity of database searching and compare it with web searching, such as World Wide Web search engines (Google, for example). The simplicity of web search engines (SEs) drive users to ask for a single search box that is able to aggregate and discover everything (Boyd et al. , 2006; Burke, 2001). The fact that SEs have succeeded in searching the surface web, but cannot easily handle the deep web resources, motivates researchers and information retrieval (IR) developers to look for new solutions for searching and discovering the deep web (Mohamed, 2006).
Deep and dynamic web resource searching requires special platforms different from those used for searching the surface web, to facilitate access to information resources hidden behind database interfaces. These unique methods of web searching lead to new platforms different from traditional surface web searching tools, such as directories, SEs and meta-search tools, because of their limitations in crawler technology and authentication requirements. On the other hand, discovering...