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.