Metrics for the Adaptation of Site Structure

This paper presents an overview of metrics for web site structure and user navigation paths. Particular attention will be paid to the question what these metrics really say about a site and its usage, and how they can be applied for adapting navigation support to the mobile context

Utility-Based Evaluation of Adaptive Systems

The variety of user-adaptive hypermedia systems available calls for methods of comparison. Layered evaluation techniques appear to be useful for this purpose. In this paper we present a utility-based evaluation approach that is based on these techniques. Issues that arise when putting utility-based evaluation into practice are dealt with. We also explain the need for interpretative user models and common sets of evaluation criteria for different domains

Revisitation Patterns and Disorientation

The non-linear structure of web sites may cause users to become disorientated. In this paper we describe the results of a pilot study to find measures of user revisitation patterns that help in predicting disorientation

Characterizations of User Web Revisit Behavior

In this article we update and extend on earlier long-term studies on user's page revisit behavior. Revisits ar

Data Cleaning Methods for Client and Proxy Logs

In this paper we present our experiences with the cleaning of Web client and proxy usage logs, based on a long-term browsing study with 25 participants. A detailed clickstream log, recorded using a Web intermediary, was combined with a second log of user interface actions, which was captured by a modified Firefox browser for a subset of the participants. The consolidated data from both records revealed many page requests that were not directly related to user actions. For participants who had no ad-filtering system installed, these artifacts made up one third of all transferred Web pages. Three major reasons could be identified: HTML Frames and iFrames, advertisements, and automatic page reloads. The experiences made during the data cleaning process might help other researchers to choose adequate filtering methods for their data

Opportunities and Challenges Around a Tool for Social and Public Web Activity Tracking

While the web contains many social websites, people are generally left in the dark about the activities of other people traversing the web as a whole. In this paper, we explore the potential benefits and privacy considerations around generating a real-time, publicly accessible stream of web activity where users can publish chosen parts of their web browsing data. Taking inspiration from social media systems, we describe individual benefits that can be unlocked by such sharing and that may incentivize users to publish aspects of their browsing. We ask whether and how these benefits outweigh potential costs in lost privacy. We conduct our study of public web activity sharing through scenario-based interviews and a field deployment of a tool for web activity sharing

Off the Beaten tracks: Exploring Three Aspects of Web Navigation

This paper presents results of a long-term client-side Web usage study, updating previous studies that range in age from five to ten years. We focus on three aspects of Web navigation: changes in the distribution of navigation actions, speed of navigation and within-page navigation. “Navigation actions” corresponding to users’ individual page requests are discussed by type. We reconfirm links to be the most important navigation element, while backtracking has lost more than half of its previously reported share and form submission has become far more common. Changes of the Web and the browser interfaces are candidates for causing these changes. Analyzing the time users stayed on pages, we confirm Web navigation to be a rapidly interactive activity. A breakdown of page characteristics shows that users often do not take the time to read the available text or consider all links. The performance of the Web is analyzed and reassessed against the resulting requirements. Finally, habits of within-page navigation are presented. Although most selected hyperlinks are located in the top left corner of the screen, in nearly a quarter of all cases people choose links that require scrolling. We analyzed the available browser real estate to gain insights for the design of non-scrolling Web pages

From Sandbox to Pandemic: Agile Reform of Canadian Drug Regulation

Public health urgency for emerging COVID-19 treatments and vaccines challenges regulators worldwide to ensure safety and efficacy while expediting approval. In Canada, legislative amendments by 2019 Om- nibus Bill C-97 created a new agile licensing framework known as the Advanced Therapeutic Pathway (ATPathway) and modernized the regulation of clinical trials of drugs, vaccines, and medical devices. Bill C-97′s amendments are worthy of attention in Canada and globally, as health product regulation bends to COVID-19. The amendments follow reforms elsewhere to accommodate health product innovation, how- ever, the Canadian ATPathway is broader and more flexible than its counterparts in other jurisdictions. In addition, Bill C-97 informed Canada’s COVID-19 response in important ways, particularly in relation to clinical trials. The measures adopted by the drug regulatory authority, Health Canada (HC) during COVID- 19 may become the new norm in Canadian regulatory practice insofar as they help achieve the amend- ments introduced by Bill C-97. Finally, despite government rhetoric of transparency, the agenda-setting, formulation, and implementation of the amendments have occurred with little opportunity for scrutiny or public engagement

Hyper-velocity impact test and simulation of a double-wall shield concept for the Wide Field Monitor aboard LOFT

The space mission LOFT (Large Observatory For X-ray Timing) was selected in 2011 by ESA as one of the candidates for the M3 launch opportunity. LOFT is equipped with two instruments, the Large Area Detector (LAD) and the Wide Field Monitor (WFM), based on Silicon Drift Detectors (SDDs). In orbit, they would be exposed to hyper-velocity impacts by environmental dust particles, which might alter the surface properties of the SDDs. In order to assess the risk posed by these events, we performed simulations in ESABASE2 and laboratory tests. Tests on SDD prototypes aimed at verifying to what extent the structural damages produced by impacts affect the SDD functionality have been performed at the Van de Graaff dust accelerator at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg. For the WFM, where we expect a rate of risky impacts notably higher than for the LAD, we designed, simulated and successfully tested at the plasma accelerator at the Technical University in Munich (TUM) a double-wall shielding configuration based on thin foils of Kapton and Polypropylene. In this paper we summarize all the assessment, focussing on the experimental test campaign at TUM.Comment: Proc. SPIE 9144, Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray, 91446