Result diversity is a topic of great importance as more facets of queries are discovered and users expect to find their desired facets in the first page of the results. However, the underlying questions of how ‘diversity ’ interplays with ‘quality’ and when preference should be given to one or both are not well-understood. In this work, we model the problem as expectation maximization and study the challenges of estimating the model parameters and reaching an equilibrium. One model parameter, for example, is correlations between pages which we estimate using textual contents of pages and click data (when available). We conduct experiments on diversifying randomly selected queries from a query log and the queries chosen from the disambiguation topics of Wikipedia. Our algorithm improves upon Google in terms of the diversity of random queries, retrieving 14 % to 38% more aspects of queries in top 5, while maintaining a precision very close to Google. On a more selective set of queries that are expected to benefit from diversification, our algorithm improves upon Google in terms of precision and diversity of the results, and significantly outperforms another baseline system for result diversification.

In response to a query, a search engine returns a ranked list of documents. If the query is about a popular topic (i.e., it matches many documents), then the returned list is usually too long to view fully. Studies show that users usually look at only the top 10 to 20 results. However, we can exploit the fact that the best targets for popular topics are usually linked to by enthusiasts in the same domain. In this paper, we propose a novel ranking scheme for popular topics that places the most authoritative pages on the query topic at the top of the ranking. Our algorithm operates on a special index of "expert documents." These are a subset of the pages on the WWW identified as directories of links to non-affiliated sources on specific topics. Results are ranked based on the match between the query and relevant descriptive text for hyperlinks on expert pages pointing to a given result page. We present a prototype search engine that implements our ranking scheme and discuss its performance. With a relatively small (2.5 million page) expert index, our algorithm was able to perform comparably on popular queries with the best of the mainstream search engines.

Previous studies of the Web graph structure have focused on the graph structure at the level of individual pages. In actuality the Web is a hierarchically nested graph, with domains, hosts and Web sites introducing intermediate levels of affiliation and administrative control. To better understand the growth of the Web we need to understand its macro-structure, in terms of the linkage between Web sites. We approximate this by studying the graph of the linkage between hosts on the Web. This was done based on snapshots of the Web taken by Google in Oct 1999, Aug 2000 and Jun 2001. The connectivity between hosts is represented by a directed graph, with hosts as nodes and weighted edges representing the count of hyperlinks between pages on the corresponding hosts. We demonstrate how such a "hostgraph" can be used to study connectivity properties of hosts and domains over time, and discuss a modified "copy model" to explain observed link weight distributions as a function of subgraph size. We discuss changes in the Web over time in the size and connectivity of Web sites and country domains. We also describe a data mining application of the hostgraph: a related host finding algorithm which achieves a precision of 0.65 at rank 3.

Article Share on When experts agree: using non-affiliated experts to rank popular topics Authors: Krishna Bharat Google Inc., 2400 Bayshore Parkway, Mountain View and Compaq, Systems Research Center, Palo Alto Google Inc., 2400 Bayshore Parkway, Mountain View and Compaq, Systems Research Center, Palo AltoView Profile , George A. Mihaila I.B.M. T.J. Watson Research, Center, 30 Saw Mill River Road, Hawthorne, NY and Department of Computer Science, University of Toronto I.B.M. T.J. Watson Research, Center, 30 Saw Mill River Road, Hawthorne, NY and Department of Computer Science, University of TorontoView Profile Authors Info & Claims WWW '01: Proceedings of the 10th international conference on World Wide WebMay 2001 Pages 597–602https://doi.org/10.1145/371920.372162Online:01 April 2001Publication History 20citation425DownloadsMetricsTotal Citations20Total Downloads425Last 12 Months8Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

We compare several algorithms for identifying mirrored hosts on the World Wide Web. The algorithms operate on the basis of URL strings and linkage data: the type of information about Web pages easily available from Web proxies and crawlers. Identification of mirrored hosts can improve Web-based information retrieval in several ways: first, by identifying mirrored hosts, search engines can avoid storing and returning duplicate documents. Second, several new information retrieval techniques for the Web make inferences based on the explicit links among hypertext documents—mirroring perturbs their graph model and degrades performance. Third, mirroring information can be used to redirect users to alternate mirror sites to compensate for various failures, and can thus improve the performance of Web browsers and proxies. We evaluated four classes of “top-down” algorithms for detecting mirrored host pairs (that is, algorithms that are based on page attributes such as URL, IP address, and hyperlinks between pages, and not on the page content) on a collection of 140 million URLs (on 230,000 hosts) and their associated connectivity information. Our best approach is one which combines five algorithms and achieved a precision of 0.57 for a recall of 0.86 considering 100,000 ranked host pairs.

This paper addresses the problem of topic distillation on the World Wide Web, namely, given a typical user query to find quality documents related to the query topic.Connectivity analysis has been shown to be useful in identifying high quality pages within a topic specific graph of hyperlinked documents.The essence of our approach is to augment a previous connectivity analysis based algorithm with content analysis.We identify three problems with the existing approach and devise algorithms to tackle them.The results of a user evaluation are reported that show an improvement of precision at 10 documents by at least 45% over pure connectivity analysis.

Article Free Access Share on Making computers easier for older adults to use: area cursors and sticky icons Authors: Aileen Worden Psychology, Georgia Institute of Technology, Atlanta, Georgia Psychology, Georgia Institute of Technology, Atlanta, GeorgiaView Profile , Nef Walker Psychology, Georgia Institute of Technology, Atlanta, Georgia Psychology, Georgia Institute of Technology, Atlanta, GeorgiaView Profile , Krishna Bharat GVR, Georgia Institute of Technology, Atlanta, Georgia GVR, Georgia Institute of Technology, Atlanta, GeorgiaView Profile , Scott Hudson GVR, Georgia Institute of Technology, Atlanta, Georgia GVR, Georgia Institute of Technology, Atlanta, GeorgiaView Profile Authors Info & Claims CHI '97: Proceedings of the ACM SIGCHI Conference on Human factors in computing systemsMarch 1997 Pages 266–271https://doi.org/10.1145/258549.258724Published:27 March 1997Publication History 193citation3,057DownloadsMetricsTotal Citations193Total Downloads3,057Last 12 Months119Last 6 weeks16 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

We motivate the use of desktop assistants in the context of web surfing and show how such a too1 may be used to support activities in both cooperative and personal surfing., By cooperative surfing we mean surfing by a community of users who choose to cooperatively and asynchronously build up knowledge structures relevant to their group.Specifically, we describe the design of an assistant called Vistabar, which lives on the Windows desktop and operates on the currently active web browser.Vistabar instances working for individual users support the authoring of annotations and shared bookmark hierarchies, and work with profiles of community interests to make findings highly available.Thus, they support a form of community memory.Visfabar also serves as a form of personal memory by indexing pages the user sees to assist in recall.We present rationale for the assistant's design, describe roles it could play to support surfing (including those mentioned above), tid suggest efficient implementation strategies where appropriate.

This full-day workshop will bring together researchers and practitioners to explore techniques for integrating personal and community recommendations into CSCW systems. Personal recommendations are tailored to an individual user, while community recommendations reflect the values or tastes of a broader community of users.

We introduce a new genre of user interface applications that can migrate from one machine to another, taking their user interface and application contexts with them, and continue from where they left off, Such applications are not tied to one user or one machine, and can roam freely over the network, rendering service to a community of users, gathering human input and interacting with people.We envisage that this will support many new agent-based collaboration metaphors.The ability to migrate executing programs has applicability to mobile computing as well.Users can have their applicatiorta travel with them, as they move from one computing environment to another.We present an elegant programming model for creating migratory applications and describe an implementation.The biggest strength of our implementation is that the details of migration are completely hidden from the application progrannneq arbitrary user interface applications can be migrated by a single "migration" command.We address system issues such as robustness, persistence and memory usage, and also human factors relating to application design, the interaction metaphor and safety.

This paper describes Doppler a new, fast algorithm for supporting concurrent, one-way constraints between objects situated in multiple address spaces. Because of their declarative nature, convenience, low amortized cost, and good match to interface tasks, constraints have been used to support a variety of user-interface activities. Unfortunately, nearly all existing constraint maintenance algorithms are sequential in nature, and cannot function effectively in a concurrent or distributed setting. The Doppler algorithm overcomes these limitations. It is a highly efficient distributed and concurrent algorithm (based on an efficient sequential algorithm for incremental, lazy updates). Doppler relies solely on asynchronous message passing, and does not require shared memory, synchronized clocks, or a global synchronization mechanism. It supports a high degree of concurrency by efficiently tracking potential cause and effect relationships between reads and writes, and allowing all causally i...

This paper describes Visual Obliq, a user interface development environment for constructing distributed, multi-user applications. Applications are created by designing the interface with a GUI-builder and embedding callback code in an interpreted language, in much the same way as one would build a traditional (non-distributed, single-user) application with a modern user interface development environment. The resulting application can be run from within the GUI-builder for rapid turnaround or as a stand-alone executable. The Visual Obliq runtime provides abstractions and support for issues specific to distributed computing, such as replication, sharing, communication, and session management. We believe that the abstractions provided, the simplicity of the programming model, the rapid turnaround time, and the applicability to heterogeneous environments, make Visual Obliq a viable tool for authoring distributed applications and groupware.

Most graphical output devices exhibit what has been termed spatial non-linearity: the effect of setting two adjacent pixels to a given value is not the same as the sum of the effects of setting those two pixels to the same value in isolation: checkerboards of different frequencies do not have the same apparent luminance.We present a method applicable to bit-mapped devices for compensating for short-range spatial non-linearity in error-diffused images.The modification to error diffusion is such that it can be used with any error diffusion technique.In essence, it consists of finding the influence of the neighbouring (output) pixels when making the decision of whether to turn on a given pixel, and passing errors computed accordingly.

Our approach to user interface animation involves simulating the interaction of a user with the interface by synthetically generating the input events that drive the session.The interaction is made explicit by displaying the behavior of input devices audio-visually.Such "animation" is both educational and functional, and has the potential to become a powerful new medium in the graphical user interface domain.We describe the construction of a general purpose tool for animating user interfaces -the animation server.Clients drive the server with textual scripts that describe the interaction.These may contain constructs for obtaining application context information at runtime and synchronizing with other media servers.We present a few potential applications for animation servers, including a groupware package for loosely coupled collaboration.