The web is trapped in the "perpetual now", and when users traverse from page to page, they are seeing the state of the web resource (i.e., the page) as it exists at the time of the click and not necessarily at the time when the link was made. Thus, a temporal discrepancy can arise between the resource at the time the page author created a link to it and the time when a reader follows the link. This is especially important in the context of social media: the ease of sharing links in a tweet or Facebook post allows many people to author web content, but the space constraints combined with poor awareness by authors often prevents sufficient context from being generated to determine the intent of the post. If the links are clicked as soon as they are shared, the temporal distance between sharing and clicking is so small that there is little to no difference in content. However, not all clicks occur immediately, and a delay of days or even hours can result in reading something other than what the author intended. We introduce the concept of a user's temporal intention upon publishing a link in social media. We investigate the features that could be extracted from the post, the linked resource, and the patterns of social dissemination to model this user intention. Finally, we analyze the historical integrity of the shared resources in social media across time. In other words, how much is the knowledge of the author's intent beneficial in maintaining the consistency of the story being told through social posts and in enriching the archived content coverage and depth of vulnerable resources?
As for the archiving aspect of our study, the existence of Memento, TimeMaps, and multi-archive aggregators has greatly facilitated research with archives. The motivation for the Memento Framework @cite_33 is achieving a tighter integration between the current web and remnants of the web of the past. Archival versions (or mementos) of web resources do exist, both in special-purpose web archives such as the Internet Archive and the on-demand WebCite archive, or in version-aware servers such as content management systems (CMS, e.g. Wikipedia) and version control systems.
@cite_33
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The Web is ephemeral. Many resources have representations that change over time, and many of those representations are lost forever. A lucky few manage to reappear as archived resources that carry their own URIs. For example, some content management systems maintain version pages that reect a frozen prior state of their changing resources. Archives recurrently crawl the web to obtain the actual representation of resources, and subsequently make those available via special-purpose archived resources. In both cases, the archival copies have URIs that are protocolwise disconnected from the URI of the resource of which they represent a prior state. Indeed, the lack of temporal capabilities in the most common Web protocol, HTTP, prevents getting to an archived resource on the basis of the URI of its original. This turns accessing archived resources into a signicant discovery challenge for both human and software agents, which typically involves following a multitude of links from the original to the archival resource, or of searching archives for the original URI. This paper proposes the protocol-based Memento solution to address this problem, and describes a proof-of-concept experiment that includes major servers of archival content, including Wikipedia and the Internet Archive. The Memento solution is based on existing HTTP capabilities applied in a novel way to add the temporal dimension. The result is a framework in which archived resources can seamlessly be reached via the URI of their original: protocol-based time travel for the Web. The Memento protocol provides a uniform approach to query individual web archives. Soon after its emergence, Memento Aggregator infrastructure was introduced that supports querying across multiple archives simultaneously. An Aggregator generates a response by issuing the respective Memento request against each of the distributed archives it covers. As the number of archives grows, it becomes increasingly challenging to deliver aggregate responses while keeping response times and computational costs under control. Ad-hoc heuristic approaches have been introduced to address this challenge and research has been conducted aimed at optimizing query routing based on archive profiles. In this paper, we explore the use of binary, archive-specific classifiers generated on the basis of the content cached by an Aggregator, to determine whether or not to query an archive for a given URI. Our results turn out to be readily applicable and can help to significantly decrease both the number of requests and the overall response times without compromising on recall. We find, among others, that classifiers can reduce the average number of requests by 77 compared to a brute force approach on all archives, and the overall response time by 42 while maintaining a recall of 0.847. With the proliferation of public web archives, it is becoming more important to better profile their contents, both to understand their immense holdings as well as support routing of requests in the Memento aggregator. To save time, the Memento aggregator should only poll the archives that are likely to have a copy of the requested URI. Using the CDX files produced after crawling, we can generate profiles of the archives that summarize their holdings and can be used to inform routing of the Memento aggregator’s URI requests. Previous work in profiling ranged from using full URIs (no false positives, but with large profiles) to using only top-level domains (TLDs) (smaller profiles, but with many false positives). This work explores strategies in between these two extremes. In our experiments, we gained up to 22 routing precision with less than 5 relative cost as compared to the complete knowledge profile without any false negatives. With respect to the TLD-only profile, the registered domain profile doubled the routing precision, while complete hostname and one path segment gave a five fold increase in routing precision. In this paper we present the results of a study into the persistence and availability of web resources referenced from papers in scholarly repositories. Two repositories with different characteristics, arXiv and the UNT digital library, are studied to determine if the nature of the repository, or of its content, has a bearing on the availability of the web resources cited by that content. Memento makes it possible to automate discovery of archived resources and to consider the time between the publication of the research and the archiving of the referenced URLs. This automation allows us to process more than 160000 URLs, the largest known such study, and the repository metadata allows consideration of the results by discipline. The results are startling: 45 (66096) of the URLs referenced from arXiv still exist, but are not preserved for future generations, and 28 of resources referenced by UNT papers have been lost. Moving forwards, we provide some initial recommendations, including that repositories should publish URL lists extracted from papers that could be used as seeds for web archiving systems. While the Internet community recognized early on the need to store and preserve past content of the Web for future use, the tools developed so far for retrieving information from Web archives are still difficult to use and far less efficient than those developed for the "live Web." We expect that future information retrieval systems will utilize both the "live" and "past Web" and have thus developed a general framework for a past Web browser. A browser built using this framework would be a client-side system that downloads, in real time, past page versions from Web archives for their customized presentation. It would use passive browsing, change detection and change animation to provide a smooth and satisfactory browsing experience. We propose a meta-archive approach for increasing the coverage of past Web pages and for providing a unified interface to the past Web. Finally, we introduce query-based and localized approaches for filtered browsing that enhance and speed up browsing and information retrieval from Web archives. With its seemingly limitless scope, the World Wide Web promises enormous advantages, along with enormous problems, to researchers who seek to use it as a source of data. Websites change continually and a high level of flux makes it challenging to capture a snapshot of the web, or even a cross-section of a small subset of the web. A web archive, such as those at the Internet Archive, promises to store and deliver repeated cross-sections of the entire web, and it also offers the potential for longitudinal analysis. Whether this potential is realized depends on the extent to which the archive has truly captured the web. Therefore, a crucial question for Internet researchers is: ‘How good are the archival data?’ We ask if there are systematic biases in the Internet Archive, using a case study to address this question. Specifically, we are interested in whether biases exist in the British websites stored in the Internet Archive data. We find that the Internet Archive contains a surprisingly small subset, about 24 , of the webpages of the website that we use for our case study (the travel site, TripAdvisor). Furthermore, the subset of data we found in the Internet Archive appears to be biased and is not a random sample of the webpages on the site. The archived data we examine has a bias toward prominent webpages. This bias could create serious problems for research using archived websites. Web archives are a huge source of information to mine the past. However, tools to explore web archives are still in their infancy, in part due to the reduced knowledge that we have of their users. We contribute to this knowledge by presenting the first search behavior characterization of web archive users. We obtained detailed statistics about the users’ sessions, queries, terms and clicks from the analysis of their search logs. The results show that users did not spend much time and effort searching the past. They prefer short sessions, composed of short queries and few clicks. Full-text search is preferred to URL search, but both are frequently used. There is a strong evidence that users prefer the oldest documents over the newest, but mostly search without any temporal restriction. We discuss all these findings and their implications on the design of future web archives. The World Wide Web is becoming a source of information for researchers, who are more aware of the possibilities for collections of Internet content as resources. Some have begun creating archives of web content for social science and humanities research. However, there is a growing gulf between policies shared between global and national institutions creating web archives and the practices of researchers making use of the archives. Each set of stakeholders finds the others’ web archiving contributions less applicable to their own field. Institutions find the contributions of researchers to be too narrow to meet the needs of the institution’s audience, and researchers find the contributions of institutions to be too broad to meet the needs of their research methods. Resources are extended to advance both institutional and researcher tools, but the gulf between the two is persistent. Institutions generally produce web archives that are broad in scope but with limited access and enrichment tools. The design of common access interfaces, such as the Internet Archive’s Wayback Machine, limit access points to archives to only URL and date. This narrow access limits the ways in which web archives can be valuable for exploring research questions in the humanities and social sciences. Individual scholars, in catering to their own disciplinary and methodological needs, produce web archives that are narrow in scope, and whose access and enrichment tools are personalized to work within the boundaries of the project for which the web archive was built. There is no way to explore a subset of an archive by topic, event, or idea. The current search paradigm in web archiving access tools is built primarily on retrieval, not discovery. We suggest that there is a need for extensible tools to enhance access to and enrichment of web archives to make them more readily reusable and so, more valuable for both institutions and researchers, and that annotation activities can serve as one potential guide for development of such tools to bridge the divide. Archiving is important for scientific data, where it is necessary to record all past versions of a database in order to verify findings based upon a specific version. Much scientific data is held in a hierachical format and has a key structure that provides a canonical identification for each element of the hierarchy. In this article, we exploit these properties to develop an archiving technique that is both efficient in its use of space and preserves the continuity of elements through versions of the database, something that is not provided by traditional minimum-edit-distance diff approaches. The approach also uses timestamps. All versions of the data are merged into one hierarchy where an element appearing in multiple versions is stored only once along with a timestamp. By identifying the semantic continuity of elements and merging them into one data structure, our technique is capable of providing meaningful change descriptions, the archive allows us to easily answer certain temporal queries such as retrieval of any specific version from the archive and finding the history of an element. This is in contrast with approaches that store a sequence of deltas where such operations may require undoing a large number of changes or significant reasoning with the deltas. A suite of experiments also demonstrates that our archive does not incur any significant space overhead when contrasted with diff approaches. Another useful property of our approach is that we use XML format to represent hierarchical data and the resulting archive is also in XML. Hence, XML tools can be directly applied on our archive. In particular, we apply an XML compressor on our archive, and our experiments show that our compressed archive outperforms compressed diff-based repositories in space efficiency. We also show how we can extend our archiving tool to an external memory archiver for higher scalability and describe various index structures that can further improve the efficiency of some temporal queries on our archive. This Note addresses the use of archived Internet content obtained via the Wayback Machine, a service provided by the Internet Archive that accesses the largest online digital collection of archived Web pages in the world. Given the dynamic nature of the World Wide Web, Internet content is constantly changed, amended, and removed. As a result, interim versions of Web pages have limited life spans. The Internet Archive indexes and stores Web pages to allow researchers to access discarded or since-altered versions. In the legal profession, archived Web pages have become an increasingly helpful form of proof. Intellectual property enforcers have recognized the value of the Internet Archive as a tool for tracking down infringers, but evidence from the Internet Archive has rarely been admitted at trial. This Note surveys the handful of judicial opinions and orders that comment on the admission of Internet Archive evidence and explores the conflict underlying these approaches. As an alternative to the courses they have taken, this Note urges courts to treat the introduction of archived Web pages as implicating a best evidence issue in addition to an authentication question. Under this approach, courts would decide using evidence sufficient to the purpose, but not necessarily admissible at trial, whether the archived page qualifies as a 'duplicate' of a page that once appeared on the Web. Beyond that, courts would apply authentication standards already developed to decide whether a reasonable jury could find, based only on admissible evidence, whether proffered evidence accurately represents the page stored on the Internet Archive server and, if necessary, whether the original page accurately represented material placed on the originating site by the site’s owner or operator. With this additional step, reliable evidence from the Wayback Machine can become as easily admitted as any other Internet-derived proof. Web archives capture the history of the Web and are therefore an important source to study how societ al developments have been reflected on the Web. However, the large size of Web archives and their temporal nature pose many challenges to researchers interested in working with these collections. In this work, we describe the challenges of working with Web archives and propose the research methodology of extracting and studying sub-collections of the archive focused on specific topics and events. We discuss the opportunities and challenges of this approach and suggest a framework for creating sub-collections. The Internet Archive, an important initiative that maintains a record of the evolving Web, has the promise of being a key resource for historians and those who study the Web itself. The archive's goal is to index the whole Web without making any judgments about which pages are worth saving. The potential importance of the archive for longitudinal and historical Web research leads to the need to evaluate its coverage. This article focuses upon whether there is an international bias in its coverage. The results show that there are indeed large national differences in the archive's coverage of the Web. A subsequent statistical analysis found differing national average site ages and hyperlink structures to be plausible explanations for this uneven coverage. Although the bias is unintentional, researchers using the archive in the future need to be aware of this problem. The Memento Project's archive access additions to HTTP have enabled development of new web archive access user interfaces. After experiencing this web time travel, the in- evitable question that comes to mind is "How much of the Web is archived?" This question is studied by approximating the Web via sampling URIs from DMOZ, Delicious, Bitly, and search engine indexes and measuring number of archive copies available in various public web archives. The results indicate that 35 -90 of URIs have at least one archived copy, 17 -49 have two to five copies, 1 -8 have six to ten copies, and 8 -63 at least ten copies. The number of URI copies varies as a function of time, but only 14.6-31.3 of URIs are archived more than once per month. An archive profile is a high-level summary of a web archive’s holdings that can be used for routing Memento queries to the appropriate archives. It can be created by generating summaries from the CDX files (index of web archives) which we explored in an earlier work. However, requiring archives to update their profiles periodically is difficult. Alternative means to discover the holdings of an archive involve sampling based approaches such as fulltext keyword searching to learn the URIs present in the response or looking up for a sample set of URIs and see which of those are present in the archive. It is the fulltext search based discovery and profiling that is the scope of this paper. We developed the Random Searcher Model (RSM) to discover the holdings of an archive by a random search walk. We measured the search cost of discovering certain percentages of the archive holdings for various profiling policies under different RSM configurations. We can make routing decisions of 80 of the requests correctly while maintaining about 0.9 recall by discovering only 10 of the archive holdings and generating a profile that costs less than 1 of the complete knowledge profile. Web archives are typically very broad in scope and extremely large in scale. This makes data analysis appear daunting, especially for non-computer scientists. These collections constitute an increasingly important source for researchers in the social sciences, the historical sciences and journalists interested in studying past events. However, there are currently no access methods that help users to efficiently access information, in particular about specific events, beyond the retrieval of individual disconnected documents. Therefore we propose a novel method to extract event-centric document collections from large scale Web archives. This method relies on a specialized focused extraction algorithm. Our experiments on the German Web archive (covering a time period of 19 years) demonstrate that our method enables the extraction of event-centric collections for different event types. Current web search engines focus on searching only themost recentsnapshot of the web. In some cases, however, it would be desirableto search over collections that include many different crawls andversions of each page. One important example of such a collectionis the Internet Archive, though there are many others. Sincethe data size of such an archive is multiple times that of a singlesnapshot, this presents us with significant performance challenges.Current engines use various techniques for index compression andoptimized query execution, but these techniques do not exploit thesignificant similarities between different versions of a page, or betweendifferent pages.In this paper, we propose a general framework for indexing andquery processing of archival collections and, more generally, anycollections with a sufficient amount of redundancy. Our approachresults in significant reductions in index size and query processingcosts on such collections, and it is orthogonal to and can be combinedwith the existing techniques. It also supports highly efficientupdates, both locally and over a network. Within this framework,we describe and evaluate different implementations that trade offindex size versus CPU cost and other factors, and discuss applicationsranging from archival web search to local search of web sites,email archives, or file systems. We present experimental resultsbased on search engine query log and a large collection consistingof multiple crawls. Organizations like the Internet Archive have been capturing Web contents over decades, building up huge repositories of time-versioned pages. The timestamp annotations and the sheer volume of multi-modal content constitutes a gold mine for analysts of all sorts, across different application areas, from political analysts and marketing agencies to academic researchers and product developers. In contrast to traditional data analytics on click logs, the focus is on longitudinal studies over very long horizons. This longitudinal aspect affects and concerns all data and metadata, from the content itself, to the indices and the statistical metadata maintained for it. Moreover, advanced analysts prefer to deal with semantically rich entities like people, places, organizations, and ideally relationships such as company acquisitions, instead of, say, Web pages containing such references. For example, tracking and analyzing a politician’s public appearances over a decade is much harder than mining frequently used query words or frequently clicked URLs for the last month. The huge size of Web archives adds to the complexity of this daunting task. This paper discusses key challenges, that we intend to take up, which are posed by this kind of longitudinal analytics: time-travel indexing and querying, entity detection and tracking along the time axis, algorithms for advanced analyses and knowledge discovery, and scalability and platform issues. The Internet Archive's Wayback Machine is the largest modern web archive, preserving web content since 1996. We discover and analyze several vulnerabilities in how the Wayback Machine archives data, and then leverage these vulnerabilities to create what are to our knowledge the first attacks against a user's view of the archived web. Our vulnerabilities are enabled by the unique interaction between the Wayback Machine's archives, other websites, and a user's browser, and attackers do not need to compromise the archives in order to compromise users' views of a stored page. We demonstrate the effectiveness of our attacks through proof-of-concept implementations. Then, we conduct a measurement study to quantify the prevalence of vulnerabilities in the archive. Finally, we explore defenses which might be deployed by archives, website publishers, and the users of archives, and present the prototype of a defense for clients of the Wayback Machine, ArchiveWatcher. In the event of emergencies and disasters, massive amounts of web resources are generated and shared. Due to the rapidly changing nature of those resources, it is important to start archiving them as soon as a disaster occurs. This led us to develop a prototype system for constructing archives with minimum human intervention using the seed URLs extracted from tweet collections. We present the details of our prototype system. We applied it to five tweet collections that had been developed in advance, for evaluation. We also identify five categories of non- relevant files and conclude with a discussion of findings from the evaluation. Web archives, such as the Internet Archive, preserve an unprecedented abundance of materials regarding major events and transformations in our society. In this paper, we present an approach for building event-centric sub-collections from such large archives, which includes not only the core documents related to the event itself but, even more importantly, documents describing related aspects (e.g., premises and consequences). This is achieved by identifying relevant concepts and entities from a knowledge base, and then detecting their mentions in documents, which are interpreted as indicators for relevance. We extensively evaluate our system on two diachronic corpora, the New York Times Corpus and the US Congressional Record; additionally, we test its performance on the TREC KBA Stream Corpus and on the TREC-CAR dataset, two publicly available large-scale web collections.