Information visibility on the Web and conceptions of success and failure in Web searching.

This thesis reports the procedure and findings of an empirical study about end users' interaction with web-based search tools. The first part is dedicated to address early research questions to discover web user's conceptions of the invisible web. The second part addresses primary research questions to explore web users' conceptualizations of the causes of their search success/failure and their awareness of and reaction to missed information while searching the web. The third part is devoted to a number of emergent research questions to reexamine the dataset in the light of a number of theoretical frameworks including Locus of Control, Self-efficacy, Attribution Theory and Bounded Rationality and Satisficing theory. The data collection was carried out in three phases based on in-depth, open-ended and semi-structured interviews with a sample of academic staff, research staff and research students from three biology-related departments at the University of Sheffield. A combination of inductive and deductive approaches was employed to address three sets of research questions. The first part of analysis which was based on Grounded Theory led to discovery of a new concept called 'information visibility' which does make a distinction between technical objective conceptions of the invisible web that commonly appear in the literature, and a cognitive subjective conception based on searchers' perceptions of search failure. Accordingly, the study introduced a 'model of information visibility on the web' which suggests a complementary definition for the invisible web. Inductive exploration of the data to address the primary research questions culminated in identification of different kinds of success (i.e. anticipated, serendipitous, and unexpected success) and failure (i.e. unexpected, unexplained and inevitable failure). The results also showed that the participants in the study were aware of the possibility of missing some relevant information in their searches and the risk of missing potentially important information is a matter of concern to them. However, regarding the context of each search they have different perceptions of the importance and the volume of missed information and accordingly they react to it differently. In view of that, two matrices including the "matrix of search impact" and the "matrix of search depth" were developed to address users' search behaviours regarding their awareness of and reaction to missed information. The matrix of search impact suggests that there are different perceptions of the risk of missing information including "inconsequential", "tolerable", "damaging" and "disastrous". The matrix of search depth illustrates different search strategies including "minimalist", "opportunistic", "nervous" and "extensive". The third part of the study indicated that Locus of Control and Attribution Theory are useful theoretical frameworks for helping us to better understand web-based information seeking. Furthermore, interpretation of the data with regards to Bounded Rationality and Satisficing theory supported the inductive findings and showed that web users' estimations of the likely volume and importance of missed information affect their decision to persist in searching. At the final stage of the study, an integrative model of information seeking behaviour on the web was developed. This six-layer model incorporates the results of both inductive and deductive stages of the study.