This application relates in general to digital information search and sensemaking and, in particular, to a system and method for using banded topic relevance and time for article prioritization.
The Worldwide Web (“Web”) is an open-ended digital information repository into which information is posted, with newer articles continually replacing less recent ones or beginning entirely new subjects of discussion. The information on the Web can, and often does, originate from diverse sources, including authors, editors, collaborators, and outside contributors commenting, for instance, through a Web log, or “Blog.” Such diversity suggests a potentially expansive topical index, which, like the underlying information, continuously grows and changes. The diversity also suggests that some of the topics in the index may be more timely, that is, “hot,” than others, which have since turned “cold” over an extended time period or have moved to the periphery of a topic.
Social indexing systems provide information and search services that organize evergreen information according to the topical categories of indexes built by their users. Topically organizing an open-ended information source, like the Web, into an evergreen social index can facilitate information discovery and retrieval, such as described in commonly-assigned U.S. Patent Application, entitled “System and Method for Performing Discovery of Digital Information in a Subject Area,” Ser. No. 12/190,552, filed Aug. 12, 2008, pending, the disclosure of which is incorporated by reference.
Social indexes organize evergreen information by topic. A user defines topics for the social index and organizes the topics into a hierarchy. The user then interacts with the system to build robust models to classify the articles under the topics in the social index. The topic models can be created through example-based training, such as described in Id., or by default training, such as described in commonly-assigned U.S. Patent Application, entitled “System and Method for Providing Default Hierarchical Training for Social Indexing,” Ser. No. ______, filed Jan. 27, 2009, the disclosure of which is incorporated by reference. Example-based training results in fine-grained topic models generated as finite-state patterns that appropriately match positive training example articles and do not match negative training example articles, while default training forms topic models in a self-guided fashion based on a hierarchical topic tree using both the individual topic labels and their locations within the tree.
In addition, the system can build coarse-grained topic models based on population sizes of characteristic words, such as described in commonly-assigned U.S. Patent Application, entitled “System and Method for Providing a Topic-Directed Search,” Ser. No. 12/354,681, filed Jan. 15, 2009, pending, the disclosure of which is incorporated by reference. The coarse-grained topic models are used to recognize whether an article is roughly on topic. Articles that match the fine-grained topic models, yet have statistical word usage far from the norm of the positive training example articles are recognized as “noise” articles. The coarse-grained topic models can also suggest “near misses,” that is, articles that are similar in word usage to the training examples, but which fail to match any of the preferred fine-grained topic models, such as described in commonly-assigned U.S. Provisional Patent Application, entitled “System and Method for Providing Robust Topic Identification in Social Indexes,” Ser. No. 61/115,024, filed Nov. 14, 2008, pending, the disclosure of which is incorporated by reference.
Thus, social indexing systems display articles within a topically-organized subject area according to the fine-grained topics in the social index, which can be selected by a user through a user interface. The topical indexing and search capabilities of these systems help users to quickly access information on topics that they specify. However, these capabilities do not address how best to meet the different information goals of individual users, which can range from focusing on the latest “news,” to catching up on recent topical articles that appeared over a few days, or to reading the most definitive articles on a topic.
The approaches used by online news, social media aggregation, and automated news aggregation Web sites, further described infra, rely on a single ordering of articles, which fails to meet the users' different information goals.
Articles in a topic are grouped into and displayed by relevance bands, such as “centrally-relevant,” “relevant,” and “somewhat relevant,” starting with the most relevant band. The articles are sorted by time within each band, and articles outside a time region are filtered out. This logic and simple control for presenting articles accommodates different user information goals and fits typical patterns of changing relevance along topic life cycles. The control does not require a novice user to articulate a complex search goal that prioritizes relevance or recency.
One embodiment provides a system and method for using banded topic relevance and time for article prioritization. Articles of digital information and at least one social index are maintained. The social index includes topics that each relate to one or more of the articles. Fine-grained topic models matched to the digital information for each topic are retrieved. The articles are succinctly classified under the topics using the fine-grained topic models. Each of the articles is relevancy scored within the topic under which the article was classified. The articles are arranged into discrete bands by relevance score. The articles are temporally sorted within the discrete bands. The articles are presented within the discrete bands.
Still other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein are described embodiments byway of illustrating the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, all without departing from the spirit and the scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
The following terms are used throughout and, unless indicated otherwise, have the following meanings:
Corpus: A collection or set of articles, documents, Web pages, electronic books, or other digital information available as printed material.
Document: An individual article within a corpus. A document can also include a chapter or section of a book, or other subdivision of a larger work. A document may contain several cited pages on different topics.
Cited Page: A location within a document to which a citation in an index, such as a page number, refers. A cited page can be a single page or a set of pages, for instance, where a subtopic is extended by virtue of a fine-grained topic model for indexing and the set of pages contains all of the pages that match the fine-grained topic model. A cited page can also be smaller than an entire page, such as a paragraph, which can be matched by a fine-grained topic model.
Subject Area: The set of topics and subtopics in a social index, including an evergreen index or its equivalent.
Topic: A single entry within a social index characterizing a topical category. In an evergreen index, a topic has a descriptive label and is accompanied.
Subtopic: A single entry hierarchically listed under a topic within a social index. In an evergreen index, a subtopic is also accompanied by one or more topic models.
Fine-grained topic model: This topic model is based on finite state computing and is used to determine whether an article falls under a particular topic. Each saved fine-grained topic model is a finite-state pattern, similar to a query. This topic model is created by training a finite state machine against positive and negative training examples.
Coarse-grained topic model: This topic model is based on characteristic words and is used in deciding which topics correspond to a query. Each saved coarse-grained topic model is a set of characteristic words, which are important to a topic, and a score indicating the importance of each characteristic word. This topic model is also created from positive training examples, plus a baseline sample of articles on all topics in an index. The baseline sample establishes baseline frequencies for each of the topics and the frequencies of words in the positive training examples are compared with the frequencies in the baseline samples. In addition to use in generating topical sub-indexes, coarse-grained models can be used for advertisement targeting, noisy article detection, near-miss detection, and other purposes.
Community: A group of people sharing main topics of interest in a particular subject area online and whose interactions are intermediated, at least in part, by a computer network. A subject area is broadly defined, such as a hobby, like sailboat racing or organic gardening; a professional interest, like dentistry or internal medicine; or a medical interest, like management of late-onset diabetes.
Augmented Community: A community that has a social index on a subject area. The augmented community participates in reading and voting on documents within the subject area that have been cited by the social index.
Evergreen Index: An evergreen index is a social index that continually remains current with the corpus.
Social Indexing System: An online information exchange infrastructure that facilitates information exchange among augmented communities, provides status indicators, and enables the passing of documents of interest from one augmented community to another. An interconnected set of augmented communities form a social network of communities.
Information Diet: An information diet characterizes the information that a user “consumes,” that is, reads across subjects of interest. For example, in his information consuming activities, a user may spend 25% of his time on election news, 15% on local community news, 10% on entertainment topics, 10% on new information on a health topic related to a relative, 20% on new developments in their specific professional interests, 10% on economic developments, and 10% on developments in ecology and new energy sources. Given a system for social indexing, the user may join or monitor a separate augmented community for each of his major interests in his information diet.
A digital information infrastructure includes public data networks, such as the Internet, standalone computer systems, and other open-ended repositories of electronically-stored information.
In general, each user device 13a-c is a Web-enabled device that executes a Web browser or similar application, which supports interfacing to and information exchange and retrieval with the servers 14a-c. Both the user devices 13a-c and servers 14a-c include components conventionally found in general purpose programmable computing devices, such as a central processing unit, memory, input/output ports, network interfaces, and non-volatile storage, although other components are possible. Moreover, other information sources in lieu of or in addition to the servers 14a-c, and other information consumers, in lieu of or in addition to user devices 13a-c, are possible.
A social indexing system 11 supplies articles topically organized under an evergreen index through social indexing, such as described in commonly-assigned U.S. Patent Application, entitled “System and Method for Performing Discovery of Digital Information in a Subject Area,” Ser. No. 12/190,552, filed Aug. 12, 2008, pending, the disclosure of which is incorporated by reference. The social indexing system 11 also determines which topics are currently “hot” and which topics have turned “cold” to meet a user's need for recent information, such as described in commonly-assigned U.S. Patent Application, entitled “System and Method for Managing User Attention by Detecting Hot and Cold Topics in Social Indexes,” Ser. No. ______, filed Jan. 27, 2009, the disclosure of which is incorporated by reference. Finally, the social indexing system 11 groups and displays articles by relevance bands, which are sorted by time and filtered by time regions, as further described below beginning with reference to
From a user's point of view, the environment 10 for digital information retrieval appears as a single information portal, but is actually a set of separate but integrated services.
The components 20 can be loosely grouped into three primary functional modules, information collection 21, social indexing 22, and user services 23. Other functional modules are possible. Additionally, the functional modules can be implemented on the same or separate computational platform. Information collection 21 obtains incoming content 24, such as Web content 15a, news content 15b, and “vetted” content 15c, from the open-ended information sources, including Web servers 14a, news aggregator servers 14b, and news servers with voting 14, which collectively form a distributed corpus of electronically-stored information. The incoming content 24 is collected by a media collector to harvest new digital information from the corpus. The incoming content 24 can typically be stored in a structured repository, or indirectly stored by saving hyperlinks or citations to the incoming content in lieu of maintaining actual copies.
The incoming content 24 may be stored in multiple representations, which differ from the representations in which the information was originally stored. Different representations could be used to facilitate displaying titles, presenting article summaries, keeping track of topical classifications, and deriving and using fine-grained topic models. Words in the articles could also be stemmed and saved in tokenized form, minus punctuation, capitalization, and so forth. Moreover, fine-grained topic models created by the social indexing system 11 represent fairly abstract versions of the incoming content 24 where many of the words are discarded.
The incoming content 24 is preferably organized under at least one topical index 29 that is maintained in a storage device 25. The topical index 29 may be part of a larger set of topical indexes 26 that covers all of the information. The topical index 29 can be an evergreen index built through social indexing 22, such as described in commonly-assigned U.S. Patent Application “System and Method for Performing Discovery of Digital Information in a Subject Area,” Ser. No. 12/190,552, filed Aug. 12, 2008, pending, the disclosure of which is incorporated by reference. The evergreen index contains fine-grained topic models, such as finite state patterns, that can be used to test whether new information falls under one or more of the topics in the index. Social indexing 22 applies supervised machine learning to bootstrap training material into the fine-grained topic models for each topic and subtopic in the topical index 29. Alternatively, social indexing 22 can perform default training to form topic models in a self-guided fashion based on a hierarchical topic tree using both the individual topic labels and their locations within the tree, such as described in commonly-assigned U.S. Patent Application, entitled “System and Method for Providing Default Hierarchical Training for Social Indexing,” Ser. No. ______, filed Jan. 27, 2009, the disclosure of which is incorporated by reference. Once trained, the evergreen index can be used for index extrapolation to automatically categorize new incoming content 24 into topics for pre-selected subject areas.
User services 23 provide a front-end to users 27a-b to access the set of topical indexes 26 and the incoming content 24, to perform search queries on the set of topical indexes 26 or a single topical index 29, and to access search results, top indexes, and focused sub-indexes. In a still further embodiment, each topical index 29 is tied to a community of users, known as an “augmented” community, which has an ongoing interest in a core subject area. The community “vets” information cited by voting 28 within the topic to which the information has been assigned.
Like news services and information retrieval services, social indexes present summaries of selected articles.
When individual users have particular information goals, some orderings of articles are better than others, especially as the order in which articles are displayed matters effects how long a user takes to reach particular information.
One way to try to meet these information goals is to provide a control that can sort articles by either time or relevance. However, some shortcomings of this approach become apparent in view of the life cycles of topics.
During the life cycle of a topic, the counts and relative relevance of articles under the topic can change.
The articles are grouped into clusters A, B, C, D, E, and F, which can be used to illustrate the typical goals for a “news reader” and a “relevance reader” on a cooling topic. These goals can be expressed as exemplary usage cases, which include:
Several alternative approaches unsatisfactorily attempt to satisfy user information needs with a single control. One approach provides a control that sorts the articles either by date or by topic. A second approach uses a degree-of-interest (DOI) function that combines relevance and age, together with a control that changes the emphasis between relevance and age. Still other approaches exist in online news Web sites. Each of these approaches is considered against the eight usage cases described supra.
Time and Relevance Sorting
One approach to meeting user goals is to enable the system to sort the articles, either by time or by relevance score, giving the user a control for selecting which priority by which to sort. Assuming that the system also filters out articles of marginal relevance, this approach satisfies only five of the eight usage cases:
Degree-of-Interest with Date and Relevance Control
Another approach to meeting user goals is to use a DOI function that considers both relevance and article age. A typical approach uses a linear function to compute a score ScoreDOI, such as:
ScoreDOI=C+w1×Relevance−w2×Age (1)
where C represents the article count, Relevance represents the topic's relevancy, and weights w1 and w2 respectively determine the relative influences of relevance and age. The articles are presented in order of descending DOI score.
In general, a DOI system is intended to work without any additional user controls for prioritizing the score. However, since a news reader's and a relevance reader's goals are in conflict, no fixed values for the weights w1 and w2 can satisfy both kinds of readers at the same time and additional user controls would be required to adjust to each of these readers needs. Alternatively, the DOI system could include a control to emphasize either time or relevance, but that control effectively converts the DOI system into a time and relevance sorting system, as described supra. This approach fails on the same cases as the previous approach, time-and-relevance sorting.
Other Related Approaches
Other related approaches to meeting user goals can be found in online news Web sites, such as provided by the Reddit, Google News Archive, and Digg Web sites. These approaches present articles with time-period controls.
The Reddit Web site presents articles with a time-filter control.
Reddit does poorly on usage cases where time-coherence is needed for the articles over an extended period of time. For example, Reddit fails usage Case 1 (hot topic, news reader) when the reader wants to see the latest articles, or the time-evolution of the articles. For similar reasons, Reddit also fails usage Case 3 (cold topic, news reader) and usage Case 5 (recurring topic, news reader). Moreover, under usage Case 1, a news reader could just set Reddit to a one-hour or one-day time window to filter articles that were beyond the current time, but no articles would be shown at all if the articles available to Reddit failed to be sufficiently recent enough. Conversely, if a news reader specified a wider time window, the most recent articles would be listed after the highest scoring articles, forcing the reader to manually search for the latest articles.
The Google News Archive Web site presents articles matching a query with a control for a time period.
Under Google News Archive, articles are presented in an order based on match scoring, but does not seem to sort articles by time. As well, like Reddit, Google News Archive is not a social indexing system and fails usage Cases 1, 3, and 5 for the same reasons as Reddit. Google News Archive presents articles matching a user query, rather than articles falling within a topical index. Finally, Google News Archive does not provide banding of scores or sorting by time within the bands.
Finally, the Digg Web site presents articles within broad subject areas with a control for a time period.
Under Digg, only those articles matching a specific user query are presented, rather than all articles falling within a topical index. As well, like Reddit, Digg is not a social indexing system and fails usage Cases 1, 3, and 5 for the same reasons as Reddit. Digg also does not provide banding of scores or sorting by time within the bands. The secondary sorting by date happens only for scores with the same number of votes. As articles can potentially receive thousands of votes, tied-article grouping is not the same as grouping articles into a few broad bands.
Different user information goals and typical patterns of changing relevance along topic life cycles can be accommodated by providing an appropriate time control combined with automated relevance ordering.
To begin, subject areas, topics within the subject areas, and sources of information must be defined (step 151), all of which can be provided by one or more social indexes. The social indexes can be created by a user as a hierarchically-structured topic tree to specify the index topics, or can originate from some other index source. Topic models for each topic are retrieved (step 152). The topic models are used to recognize articles and to classify newly-arriving articles by topic, which renders the social index evergreen. Each article includes both the article's content and publication date, or other indication of recency. The social index contains fine-grained topic models, such as finite state patterns, that can be used to test whether new information falls under one or more of the topics in the index. To supplement the fine-grained topic models. the social index can optionally include coarse-grained topic models are used to broadly classify the articles by recognizing whether an article is roughly on topic. Thereafter, articles are collected and succinctly classified into the social index from the information sources using the fine-grained topic models (step 153). The relevance bands for the fine-grained topics are created (step 154), as further described below with reference to
The combination of relevance banding and time sorting prioritizes relevance or recency without requiring a novice user to articulate a complex search goal.
Articles are divided into relevance bands.
Within each band, the articles are then sorted by time (step 173).
A time control is a control that limits the collected articles to a particular period.
In the simplest version, the time period control 163 starts with “now” and admits articles in one of several periods.
In contrast to a control that governs sorting and a control that governs degree-of-interest preference setting, as both discussed supra, the time period control 163 does not introduce trade-offs or concepts of “relevance versus time,” and the apparent simplicity of this approach results in an advantage to novice users seeking to satisfy their information goals. As well, the combination of the banded relevance determination and the time-filter control is capable of satisfying all eight of the usage cases:
In a further embodiment, a scoring method that scores using only a very small number of levels could be employed. For example, relevance scoring could be performed on only four levels: “extremely relevant,” “highly relevant,” “relevant,” and “not relevant.” No reduction to bands would be needed since there are only four levels. However, sorting within the bands would still be needed to exhibit the desired behavior on the eight usage cases.
In a further embodiment, the methodology can be applied to one or more social indexes within a social indexing system. The topical banding is applied within the context of each social index.
While the invention has been particularly shown and described as referenced to the embodiments thereof, those skilled in the art will understand that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope.