El gran volumen de datos que las técnicas de minería Web generan sobre espacios Web puede llegar a ser muy difícil de entender, provocando la necesidad de desarrollar nuevas técnicas que permitan generar conocimiento sobre esos datos con el fin de facilitar la toma de decisiones. Esta tesis explora la utilización de técnicas de InfoVis/VA para ayudar en la exploración de espacios Web. Más concretamente, presentamos el desarrollo de un prototipo muy flexible que ha sido utilizado para analizar tres tipos distintos de espacios Web con distintas metas informacionales: el análisis de la usabilidad de páginas Web, la evaluación del comportamiento de los estudiantes en entornos virtuales de aprendizaje y la exploración de la estructura de grandes conversaciones asíncronas existentes en foros online. Esta tesis pretende aceptar el reto propuesto por la comunidad de InfoVis/VA de llevar a cabo investigaciones en condiciones más reales, introduciendo los problemas relacionados con el análisis de los espacios Web ya mencionados, y explorando las ventajas de utilizar las visualizaciones proporcionadas por nuestra herramienta con usuarios reales. / The vast amount of data that Web mining techniques generate from Web spaces is difficult to understand, suggesting the need to develop new techniques to gather insight into them in order to assist in decision making processes. This dissertation explores the usage of InfoVis/VA techniques to assist in the exploration of Web spaces. More specifically, we present the development of a customisable prototype that has been used to analyse three different types of Web spaces with different information goals: the analysis of the usability of a website, the assessment of the students in virtual learning environments, and the exploration of the structure of large asynchronous conversations existing in online forums. Echoing the call of the Infovis/VA community for the need for more research into realistic circumstances, we introduce the problems of the analysis of such Web spaces, and further explore the benefits of using the visualisations provided by our system with real users. / El gran volum de dades que les tècniques de mineria Web proporcionen sobre els espais Web és generalment molt difícil dʼentendre, provocant la necessitat de desenvolupar noves tècniques que permetin generar coneixement sobre les dades de manera que facilitin la presa de decissions. Aquesta tesi explora la utilizació de tècniques dʼInfovis/VA per ajudar en lʼexploració dʼespais Web. Més concretament, presentem el desenvolupament dʼun prototipus molt flexible que hem utilitzat per analitzar tres tipus diferents dʼespais Web amb diferents objectius informacionals: lʼanèlisi de la usabilitat de pàgines Web, lʼavaluació del comportament dels estudiants en entorns virtuals dʼaprenentatge i lʼexploració de lʼestructura de grans converses asíncrones existents en fòrums online. Aquesta tesi pretén acceptar el repte proposat per la comunitat dʼInfoVis/VA de fer recerca en condicions més reals, introduint els problemes relacionats en lʼanàlisi dels espais Web ja esmentats, i explorant els avantatges dʼutilizar les visualitzacions proporcionades per la nostra eina amb usuaris reals.

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.

Abstract Skin diseases are common: one in every three of all general practice patients have at least one dermatological problem. However, epidemiological studies addressing the overall prevalence of skin diseases are sparse. The skin is the largest organ in the body and it has several vital and immunological functions. Cutaneous signs are often the first manifestation of many systemic diseases. The aim of this study was to determine the overall prevalence, and the distribution according to sex and socioeconomic status, of skin diseases in an adult population. The study particularly focused on multiple melanocytic naevi and their risk factors because multiple melanocytic naevi are the strongest risk factor for melanoma. A further aim was to analyse the association between cutaneous disorders and systemic conditions; specifically to determine whether abnormal skin findings in toe webs have an association with abnormal glucose metabolism and whether skin diseases have a relationship with systemic low-grade inflammation. For these purposes a comprehensive dermatological evaluation was performed as a part of the 46-year follow-up survey of the Northern Finland Birth Cohort 1966. Data on this cohort have been collected since birth. Numerous laboratory tests were also performed cross-sectionally during the 46-year follow-up survey, including an oral glucose tolerance test and the measurement of fasting plasma glucose and glycated haemoglobin fraction. High sensitivity C-reactive protein was measured as a marker of low-grade inflammation. Over half (60%) of the 1 932 individuals examined had at least one skin disorder requiring further treatment. The need for treatment was more common in males and those with lower socioeconomic status. Multiple melanocytic naevi were found in 12% of individuals; high educational level, male sex and fair skin type increased the risk. Abnormal skin findings in toe web spaces was associated with undiagnosed type 2 diabetes. Atopic eczema, rosacea and onychomycosis were associated with low-grade inflammation. This unique study with nearly 2 000 subjects reports for the first time the overall prevalence of skin diseases in an unselected Finnish population. Its findings support the previous postulate that skin diseases are common in adults and suggest that skin evaluation should be an essential part of routine medical examinations in clinical practice. / Tiivistelmä Ihotaudit ovat yleisiä, ja jopa 30 %:lla yleislääkärin potilaista on jokin ihoon liittyvä ongelma. Väestötason tutkimuksia ihotaudeista on kuitenkin niukasti. Iho on ihmisen suuri elin, ja sillä on useita tärkeitä tehtäviä, kuten osallistuminen immunologiseen puolustukseen. Monet yleissairaudet voivat näkyä iholla jo ennen taudin puhkeamista ja ihoilmentymät voivat olla varhaisia merkkejä piilevästä sairaudesta. Tämän tutkimuksen tarkoituksena oli määrittää ihotautien esiintyvyys aikuisväestössä sekä ihotautien jakautuminen sukupuolen ja sosiaalisen aseman suhteen. Lisäksi tarkoituksena oli selvittää runsasluomisuuden (yli 50 pigmenttiluomea) esiintyvyyttä ja sen riskitekijöitä, sillä runsasluomisuus on melanooman merkittävin riskitekijä. Tutkimuksen tavoitteena oli myös selvittää ihotautien yhteyttä yleissairauksiin, kuten poikkeavien varvasvälilöydösten yhteyttä häiriintyneeseen sokeriaineenvaihduntaan sekä matala-asteisen tulehduksen ja ihotautien välistä yhteyttä. Osana Pohjois-Suomen syntymäkohortti 1966:n 46-vuotistarkastusta tehtiin kokonaisvaltainen ihon tutkiminen yhteensä 1 932:lle tutkimushenkilölle vuosina 2012–13. Samassa yhteydessä tutkittavilta määritettiin paastoverensokeri ja pitkäaikainen verensokeri sekä tehtiin sokerirasitustesti sokeriaineenvaihdunnan häiriön toteamiseksi. Matala-asteisen tulehduksen arvioimiseksi määritettiin herkkä C-reaktiivinen proteiini. Tutkimusjoukon pitkäaikaiset taustatiedot perustuivat syntymäkohortin aiempiin aineistoihin. Tutkittavista 60 %:lla todettiin jokin hoitoa vaativa ihotauti. Hoidon tarve oli suurempaa miehillä ja matalammissa sosiaaliluokissa. Runsasluomisuutta esiintyi 12 %:lla, ja korkea koulutustaso, miessukupuoli ja vaalea ihotyyppi lisäsivät riskiä. Varvasväleissä esiintyvät muutokset liittyivät diagnosoimattomaan diabetekseen. Atooppinen ihottuma, ruusufinni ja kynsien sieni-infektioon sopivat muutokset olivat yhteydessä matala-asteiseen tulehdukseen. Tämä lähes 2 000 henkilön koko ihon kliiniseen tutkimukseen perustuva työ raportoi ensimmäistä kertaa ihotautien yleistä esiintyvyyttä suomalaisessa, valikoitumattomassa väestössä. Tutkimus tukee aiempaa oletusta, jonka mukaan ihotaudit ovat aikuisväestössä yleisiä; ihon tutkiminen tulisi olla oleellinen osa potilaan kliinistä perustutkimusta.