A problem common to all current web link analyses is that, as the web is continuously evolving, any web-based study may be out of date by the time it is published in academic literature. It is therefore important to know how web link analyses results vary over time, with a low rate of variation lengthening the amount of time corresponding to a tolerable loss in quality. Moreover, given the lack of research on how academic web spaces change over time, from an information science perspective it would interesting to see what patterns and trends could be identified by longitudinal research and the study of university web links seems to provide a convenient means by which to do so. The aim of this research is to identify and track changes in three academic webs (UK, Australia and New Zealand) over time, tracking various aspects of academic webs including site size and overall linking characteristics, and to provide theoretical explanations of the changes found. This should therefore provide some insight into the stability of previous and future webometric analyses. Alternative Document Models (ADMs), created with the purpose of reducing the extent to which anomalies occur in counts of web links at the page level, have been used extensively within webometrics as an alternative to using the web page as the basic unit of analysis. This research carries out a longitudinal study of ADMs in an attempt to ascertain which model gives the most consistent results when applied to the UK, Australia and New Zealand academic web spaces over the last six years. The results show that the domain ADM gives the most consistent results with the directory ADM also giving more reliable results than are evident when using the standard page model. Aggregating at the site (or university) level appears to provide less consistent results than using the page as the standard unit of measure, and this finding holds true over all three academic webs and for each time period examined over the last six years. The question of whether university web sites publish the same kind of information and use the same kind of hyperlinks year on year is important from the perspective of interpreting the results of academic link analyses, because changes in link types over time would also force interpretations of link analyses to change over time. This research uses a link classification exercise to identify temporal changes in the distribution of different types of academic web links, using three academic web spaces in the years 2000 and 2006. Significant increases in ‘research oriented’, ‘social/leisure’ and ‘superficial’ links were identified as well as notable decreases in the ‘technical’ and ‘personal’ links. Some of these changes identified may be explained by general changes in the management of university web sites and some by more wide-spread Internet trends, e.g., dynamic pages, blogs and social networking. The increase in the proportion of research-oriented links is particularly hopeful for future link analysis research. Identifying quantitative trends in the UK, Australian and New Zealand academic webs from 2000 to 2005 revealed that the number of static pages and links in each of the three academic webs appears to have stabilised as far back as 2001. This stabilisation may be partly due to an increase in dynamic pages which are normally excluded from webometric analyses. In response to the problem for webometricians due to the constantly changing nature of the Internet, the results presented here are encouraging evidence that webometrics for academic spaces may have a longer-term validity than would have been previously assumed. The relationship between university inlinks and research activity indicators over time was examined, as well as the reasons for individual universities experiencing significant increases and decreases in inlinks over the last six years. The findings indicate that between 66% and 70% of outlinks remain the same year on year for all three academic web spaces, although this stability conceals large individual differences. Moreover, there is evidence of a level of stability over time for university site inlinks when measured against research. Surprisingly however, inlink counts can vary significantly from year to year for individual universities, for reasons unrelated to research, underlining that webometric results should be interpreted cautiously at the level of individual universities. Therefore, on average since 2001 the university web sites of the UK, Australia and New Zealand have been relatively stable in terms of size and linking patterns, although this hides a constant renewing of old pages and areas of the sites. In addition, the proportion of research-related links seems to be slightly increasing. Whilst the former suggests that webometric results are likely to have a surprisingly long shelf-life, perhaps closer to five years than one year, the latter suggests that webometrics is going to be increasingly useful as a tool to track research online. While there have already been many studies involving academic webs spaces, and much work has been carried out on the web from a longitudinal perspective, this thesis concentrates on filling a critical gap in current webometric research by combining the two and undertaking a longitudinal study of academic webs. In comparison with previous web-related longitudinal studies this thesis makes a number of novel contributions. Some of these stem from extending established webometric results, either by introducing a longitudinal aspect (looking at how various academic web metrics such as research activity indicators, site size or inlinks change over time) or by their application to other countries. Other contributions are made by combining traditional webometric methods (e.g. combining topical link classification exercises with longitudinal study) or by identifying and examining new areas for research (for example, dynamic pages and non-HTML documents). No previous web-based longitudinal studies have focused on academic links and so the main findings that (for UK, Australian and New Zealand academic webs between 2000 and 2006) certain academic link types exhibit changing patterns over time, approximately two-thirds of outlinks remain the same year on year and the number of static pages and links appears to have stabilised are both significant and novel.
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