Designing A General Deep Web Access Approach Based On A Newly Introduced Factor; Harvestability Factor (HF)

The growing need of accessing more and more information draws attentions to huge amount of data hidden behind web forms defined as deep web. To make this data accessible, harvesters have a crucial role. Targeting different domains and websites enhances the need to have a general-purpose harvester which can be applied to different settings and situations. To develop such a harvester, a number of issues should be considered. Among these issues, business domain features, targeted websites' features, and the harvesting goals are the most influential ones. To consider all these elements in one big picture, a new concept, called harvestability factor (HF), is introduced in this paper. The HF is defined as an attribute of a website (HF_w) or a harvester (HF_h) representing the extent to which the website can be harvested or the harvester can harvest. The comprising elements of these factors are different websites' (for HF_w) or harvesters' (for HF_h) features. These features are presented in this paper by gathering a number of them from literature and introducing new ones through the authors' experiments. In addition to enabling websites' or harvesters' designers of evaluating where they products stand from the harvesting perspective, the HF can act as a framework for designing general purpose deep web harvesters. This framework allows filling in the gap in designing general purpose harvesters by focusing on detailed features of deep websites which have effects on harvesting processes. The represented features in this paper provide a thorough list of requirements for designing deep web harvesters which is not done to best of our knowledge in literature in this extent. To validate the effectiveness of HF in practice, it is shown how the HFs' elements can be applied in categorizing deep websites and how this is useful in designing a harvester. To run the experiments, the developed harvester by the authors, is also discussed in this paper.