Abstract:
A home evergreen index and frontier evergreen indexes are maintained. The indexes cover topically-limited subject areas, which include digital information. Each index defines a hierarchy of topics. Each index further matches a topic model to the topic hierarchy&#39;s topics. Each topic model includes a pattern evaluable against the digital information, which identifies such digital information matching the topic model&#39;s topic. At least one frontier evergreen index that includes topics that are at least partially distinct from the topics included in the home evergreen index is identified. Vetted assessments for articles identified by the at least one frontier evergreen index are obtained. The articles corresponding to the vetted assessments that are favorable are selected. The patterns that include the topic models of the home evergreen index are matched against the selected articles of the digital information. The selected articles of the digital information that were matched are provided on a display.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This patent application is a continuation of U.S. patent application Ser. No. 12/190,560, filed Aug. 12, 2008, pending, which claims priority from U.S. Provisional Patent Application Ser. No. 60/998,636, filed Oct. 12, 2007, the priority filing dates of which are claimed, and the disclosures of which are incorporated by reference. 
    
    
     FIELD 
     This application relates in general to digital information sensemaking and, in particular, to a computer-implemented system and method for prospecting digital information through online social communities. 
     BACKGROUND 
     Digital sensemaking is sensemaking mediated by a digital information infrastructure, such as the Worldwide Web (“Web”). Through the Web, users can access both “traditional” Web sites that post information from diverse sources and interactive Web sites, including moderated Web logs or “blogs,” user forums, and Web sites with voting, which allow users to actively rank new information. 
     As a digital information repository, the Web continually evolves as events occur, ideas get synthesized, and new trends emerge. New information is posted continuously. Information awareness, though, remains artificially constrained. Mainstream media Web sites generally only cover popular topics, such as news, business, politics, sports, entertainment, and weather, but a host of additional topics exist through other Web sources, which may fall outside the scope of a reader&#39;s, or publisher&#39;s, core set of interests. These topics range from slightly less popular topics, for instance, technology news, to specialized or obscure topics that are relevant to a comparatively small number of people, such as evening class schedules for a local community college. 
     The demand for items in many markets follows a “Long Tail” distribution, such as described in C. Anderson,  The Long Tail: Why the Future of Business is Selling Less of More , (Hyperion Press) (2006), the disclosure of which is incorporated by reference.  FIG. 1  is a graph showing, by way of example, a hypothetical long tail distribution  10  for digital information. The x-axis represents digital information and the y-axis represents popularity level. Items appearing at the head of the distribution  11 , although few in number, enjoy the greatest popularity, such as media stories falling into a small number of popular categories. However, items along the “long tail”  12 , which cover niche topics with smaller readerships, outnumber head items  11 . Although any single head item  11  enjoys greater popularity than any one of the long tail items  12 , the aggregate popularity of a large enough group of long tail items  12  will exceed the popularity of all head items  11  when enough long tail items  12  are included, which implies that a larger overall audience could be reached by focusing on long tail topics, provided the audience can be made aware of them. 
     Consumers of information have only a limited amount of time and cannot pay attention to everything. As more topics become available, mainstream topics receive a shrinking fraction of readers&#39; attention. Analogously, prime time television audiences are currently shrinking, as cable and satellite networks improve their programming and increase their viewership. Similarly, musical “hits” today sell fewer copies than sold a decade ago, as more choices and purchasing options become available. The economics and popularity trends from these observations can be succinctly summarized: “if you give people choices, they take them” and “the head of the distribution is shrinking.” 
     The problem is not only finding new or popular information: the problem is finding new information falling outside areas of core topical interests that nevertheless remain relevant while simultaneously pushing the envelope. Myopia sets in easily and focusing on only familiar and known topics risks missing new ideas or emerging trends. The amount of information on the “frontier” of a reader&#39;s core set of topics is larger than the body of information in main focus. Moreover, fringe topics are generally less important to the reader than the core topics, and are thus more easily overlooked. 
     Topics that will become important to readers often make their first appearance just beyond the boundaries of their familiar core topics. Monitoring topics on this fringe can give “beyond the radar” awareness of what&#39;s coming, potentially saving the expense of late remedies if attention is paid to the information much later. Efficiently finding relevant frontier information, though, can be a challenge, as the level of expertise is inherently lower than possessed for identifying core topical information. This problem is exacerbated by an incomplete understanding of the frontier information topics structure and a lack of awareness in identifying good sources of frontier information. 
     Therefore, a need remains in digital sensemaking for efficiently prospecting new, relevant, and authoritative digital information lying beyond the core topics for a specific subject area. 
     SUMMARY 
     A computer-implemented system and method for prospecting digital information through online social communities provides what&#39;s new, what&#39;s true, and what matters. “What&#39;s new” generally refers to information about current events, but in another sense, “what&#39;s new” includes new topics to which we are not yet attending. Such topics of emerging interest often come from the frontier. “What&#39;s true” means information from multiple “frontier” sources has already been socially vetted to establish level of interest and authoritativeness. “What matters” means that information is automatically categorized according to important topics in a reader&#39;s subject area. 
     New and relevant digital information is discovered by a reader&#39;s “home,” that is, usual frontier community and by neighboring frontier communities. Each community of readers discovers information by utilizing fine-grained topical indexes sheparded by knowledge domain experts, the “hard work of the few;” by aggregating rankings and suggestions about better categorizing by a large community of users, “the light work of the many” or “the wisdom of crowds;” and by extending the topical indexes though machine-assisted learning, the “tireless work of the machines.” Each augmented community has an evergreen index, which includes topic models, such as patterns, for each topic and subtopic that can be used to test whether given material is on point. The term “evergreen” is intended to connote a quality of freshness and currency for an index, so that new articles will be classified automatically and added to the index when they appear and that new topics can be added to the index as needed. 
     Digital information is prospected from the perspective of a given or “home” augmented community of a reader. One or more augmented communities on the information “frontier” of the home augmented community are first identified, either through knowledge-domain expertise or through automated suggestion of candidate frontier communities. The degree of interest assigned to articles appearing under the frontier augmented community&#39;s evergreen index is determined as an initial estimate of the relevancy the frontier information may have under the augmented community&#39;s evergreen index. The more promising articles of frontier information are then combined under the augmented community&#39;s evergreen index for collective vetting, along with articles already directly vetted under the index. 
     One embodiment provides a computer-implemented system and method for prospecting digital information through online social communities through online social communities. A home evergreen index for a home community and a plurality of frontier evergreen indexes for respective frontier communities are maintained. The home evergreen index and the frontier evergreen indexes cover topically-limited subject areas. Each of the subject areas include electronically-stored digital information. The home evergreen index and each frontier evergreen index define a hierarchy of stored topics. The home evergreen index and each frontier evergreen index further match a stored topic model to each of the topics in the topic hierarchy. Each of the topic models includes a pattern evaluable against the digital information, wherein the pattern identifies such digital information matching the topic model&#39;s topic. At least one frontier evergreen index that includes stored topics that are at least partially distinct from the stored topics included in the home evergreen index is identified. Vetted assessments as provided by the frontier community of the at least one frontier evergreen index for articles of the digital information identified by the patterns that comprise the topic models of the at least one frontier evergreen index are obtained. The articles of the digital information corresponding to the vetted assessments that are favorable are selected. The patterns that include the topic models of the home evergreen index are matched against the selected articles of the digital information. The selected articles of the digital information that were matched are provided on a display. 
     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 by way 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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a graph showing, by way of example, a hypothetical long tail distribution for digital information. 
         FIG. 2  is a functional block diagram showing challenges in digital sensemaking. 
         FIG. 3  is a block diagram showing an exemplary environment for digital information sensemaking. 
         FIG. 4  is a functional block diagram showing principal components used in the social indexing system of  FIG. 3 . 
         FIG. 5  is a graph showing, by way of example, the current organizational landscape of providers of digital information. 
         FIG. 6  is a data flow diagram showing an overview of evergreen index training. 
         FIG. 7  is a block diagram showing, by way of example, neighborhoods of augmented communities. 
         FIG. 8  is a data flow diagram showing a method for prospecting digital information in accordance with one embodiment. 
         FIG. 9  is a flow diagram showing a routine for identifying frontier augmented communities for use with the method of  FIG. 8 . 
         FIG. 10  is a flow diagram showing a routine for determining degree of interest for use with the method of  FIG. 8 . 
         FIG. 11  is a flow diagram showing a routine for relating frontier information for use with the method of  FIG. 8 . 
         FIG. 12  is a screen shot diagram showing, by way of example, a user interface providing digital information organized by degree of interest. 
     
    
    
     DETAILED DESCRIPTION 
     Glossary 
     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 topic model and the set of pages contains all of the pages that match the topic model. A cited page can also be smaller than an entire page, such as a paragraph, which can be matched by a topic model. 
     Subject Area: The set of topics and subtopics in a social index, including an evergreen index. 
     Topic: A single entry within a social index. In an evergreen index, a topic is accompanied by a topic model, such as a pattern, that is used to match documents within a corpus. 
     Subtopic: A single entry hierarchically listed under a topic within a social index. In an evergreen index, a subtopic is also accompanied by a topic model. 
     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. 
     Digital Sensemaking 
     The Web and other online information resources provide an ever-evolving and expanding source of digital information. Digital sensemaking is about making sense out of the information in these resources.  FIG. 2  is a functional block diagram  20  showing challenges in social indexing  21 : digital information discovery  22 , prospecting  23 , and orientation  24 . Other challenges are possible. These challenges represent different facets of information foraging, which work synergistically to provide new, relevant, and authoritative digital information through a topically fine-grained and socially-vetted infrastructure. Each challenge will now be summarized. 
     Digital information discovery  22  focuses on identifying new and topically-relevant information for a set of core interests, as further 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. Digital information discovery begins with the premise that each person has a set of core interests with a need for information spanning multiple topics within the core interests, including long tail topics, with varying levels of importance. The key challenge is in efficiently tracking new information on the core interests. 
     Digital information prospecting  23 , the focal point of this application, focuses on foraging or mining an individual&#39;s information frontier as an aid to idea synthesis, as further described below beginning with reference to  FIG. 7 . Information prospecting expands an individual&#39;s information diet beyond existing interests, as fundamentally satisfied through digital information discovery  22 , by tapping into a social network of communities. For example, information frontiers for local news includes news from neighboring towns and cities. As another example, information frontiers for a professional interest, such as family dentistry, potentially includes relevant topics from related fields, for instance, dental hygiene, new dental materials, and perhaps new antibiotics or results from cosmetic dentistry. Digital information prospecting facilitates efficient attention allocation without risking the distractions or inefficiencies in covering uncharted new topical ground. The key challenge is in finding the most relevant information from neighboring subject areas along the frontier. 
     Finally, digital information orientation  24  is about becoming oriented to an unfamiliar subject area, as further described in commonly-assigned U.S. patent application, entitled “System and Method for Providing Orientation into Digital Information,” Ser. No. 12/190,557, filed Aug. 12, 2008, pending, the disclosure of which is incorporated by reference. Digital information orientation is about efficiently gaining an understanding of a new subject area. This activity is complementary to information discovery and prospecting information frontiers, reflecting the case where the objective is to explore an area to learn about the subject matter generally. The activity includes learning the topic structure and main results, as well as identifying good references. 
     Digital Information Sensemaking Environment 
     Digital sensemaking is sensemaking mediated by a digital information infrastructure, which includes public data networks, such as the Internet, standalone computer systems, and various repositories of digital information.  FIG. 3  is a block diagram showing an exemplary environment  30  for digital information sensemaking. The same basic system components are utilized for digital information discovery  22 , prospecting  23 , and orientation  24 . 
     Digital information is information available in digital form. A digital data communications network  31 , such as the Internet, provides a suitable digital information exchange infrastructure, although other infrastructures are possible, for instance, a non-public corporate enterprise network. The network  31  provides interconnectivity to various information sources and information consumers that respectively provide and access the digital information. Web servers  34   a , news aggregator servers  34   b , news servers with voting  34   c , and other digital information repositories serve as information sources. These sources respectively serve Web content  35   a , news content  35   b , community-voted or “vetted” content  35   c , and other digital information to user devices  33   a - c , such as personal computers and similar devices, that function as the information consumers. 
     In general, each user device  33   a - c  is a Web-enabled device that executes a Web browser or similar application, which supports interfacing to and information exchange with the servers  34   a - c . Both the user devices  33   a - c  and servers  34   a - 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  34   a - c , and other information consumers, in lieu of or in addition to user devices  33   a - c , are possible. 
     Digital sensemaking and, in particular, digital information prospecting  23 , is facilitated by a social indexing system  32 , which is also interconnected to the information sources and the information consumers via the network  31 . The social indexing system  32  facilitates the automated prospecting of digital information from frontier augmented communities with relation to core topics within a reader&#39;s subject area. 
     Social Indexing System 
     From a user&#39;s point of view, the social indexing system appears as a single information portal, but is actually a set of services provided by an integrated digital information processing environment.  FIG. 4  is a functional block diagram showing principal components  40  used in the social indexing system  32  of  FIG. 3 . The components are focused on digital information prospecting and other components may be used to provide digital information discovery, orientation, degree of interest, and other services. 
     The components  40  can loosely be grouped into three functional areas, information collection  41 , prospecting and analysis  42 , and user services  43 , although other functional areas are possible. The functional groups are interconnected and interdependent and can be implemented on the same or separate computational platforms. Information collection  41  obtains incoming content  46 , such as Web content  35   a , news content  35   b , and “vetted” content  35   c , from information sources, including Web servers  34   a , news aggregator servers  34   b , and news servers with voting  34   c . The information sources include feeds and sources providing content to both a home augmented community, as well as select neighboring frontier communities from whom information has been prospected. The incoming content  46  is collected by a media collector operating under the direction of a scheduler to periodically or on-demand harvest new information from the information sources. The incoming content  46  can be stored in structured repository, or indirectly stored by saving only references or citations to the incoming content in lieu of maintaining an actual copy of the incoming content locally, such as storing hyperlinks. 
     Prospecting and analysis  42  tracks information not of core interest and effectively diverts a percentage of the reader&#39;s attention to frontier news. A frontier community identifier  44  locates those neighboring augmented communities that lie on the “frontier” of an augmented community&#39;s core subject areas, and identifies their information sources to information collection  41 , as further described below with reference to  FIG. 9 . The frontier information integrator  45  thereafter determines a degree of interest that is used in ranking articles received from the frontier communities and relates collected frontier information to topics and sub-topics appearing in the augmented community&#39;s evergreen index, as further described below with reference to  FIGS. 10 and 11 . 
     Finally, user services  43  provide a front-end to users  48   a - b  to access the distributed indexes  47  and the incoming content  46 . Each evergreen index  49  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  50  within the topic to which the information has been assigned, as further discussed below beginning with  FIG. 12 . 
     Digital Information Discovery 
     An information “diet” characterizes what information a user consumes across subjects of special interest, as well as select content from frontier augmented communities. The diet also reflects the amount of time that the user is willing to allocate to “digesting” each subject. Digital information prospecting contributes to the first aspect of a diet, information in subjects of special interest. 
     Prospecting relevant and authoritative digital information from outside a set of core topics to meet a user&#39;s information diet is important. Although all manner of data is widely available online, “raw” digital information obtained directly from a source generally lacks a comprehensive organizational scheme and competent ranking methodology.  FIG. 5  is a graph  60  showing, by way of example, the current organizational landscape of providers of digital information. The bidirectional x-axis represents degree of topical organization of digital information and the bidirectional y-axis represents the amount of critical review, that is, “vetting.” Information at the far left  62  of the x-axis lacks cohesive topical organization and refers to a single subject area. Under conventional approaches, the information is fairly static and organization is limited to a few topics. Information at the far right  63  of the x-axis enjoys a fine-grained and rich topical organization and covers multiple subject areas. Each subject area is deeply organized into many subtopics. 
     The y-axis characterizes the amount of expertise and labor that is used for “vetting” and ranking articles. No editing is performed on articles at the bottom of the y-axis and the articles are presented without any vetting. Closer to the origin  61 , a small team of up to a few editors are engaged in vetting articles. Higher on the y-axis, a single community of people, “the light work of the many” and “the wisdom of the crowd,” actively reads and votes on, or vets, articles. Multiple communities vet articles at the top of the y-axis, where each community focuses on a specific subject area. 
     At best, current approaches are coarsely organized and only lightly critically weighed, or “vetted.” For instance, in the southwest quadrant, conventional organizational approaches use either a broad, coarse grained, or non-existent topical organization  62  with vetting by few or no editors  64 . Specialty Web sites  66 , such as Audiophilia, available at www.audiophilia.com, and hybridcars, available at www.hybridcars.com, serve narrow readership bases sheparded by a single dedicated editor with subject matter centered on a niche topic under which further topical organization is neither needed nor desired. RSS readers  67 , such as Google reader, available at www.google.com/reader, automatically report new information under an automated feed on a dedicated topic. Similarly, automated mainstream media Web sites  68 , such as Google news, available at news.google.com, use limited popular news categories under which information is automatically grouped without the need for an editor. The categorizing of articles, however, is limited by a very course grain, where the classification of articles in such broad categories can be done by selecting articles from single-topic sources, such as technology or sports news. Finally, mainstream media Web sites  69 , such as the New York Times, available at www.nytimes.com, and c|net, available at www.cnet.com, employ individual editors or small teams of editors that organize news into popular news categories, which may include a wider scope to topics than available through automated mainstream media Web sites  68 . The lack of community-based and presumptively impartial vetting, and the lack of fine-grained topic organization prevent these approaches from providing information covering a wide range of subject areas that is relevant to augmented communities that are interested in them, or to neighboring communities who may be interested in them. 
     In slight contrast, in the northwest quadrant, current approaches also use either a broad, coarse grained, or non-existent topical organization  62  and offer vetting by individual or small communities of users  65 . Blog search engines  70 , such as Google blog search, available at googleblog.blogspot.com, and icerocket, available at www.icerocket.com, are Web search engines dedicated to blogs, but the blogs are passively searched without use of topical organization. News aggregators  71 , such as Topix, available at www.topix.com, automatically collect news organized by zip code into broad, and usually popular, topic areas with limited community-based review. Finally, news Web sites with voting  72 , such as Slashdot, available at www.slashdot.org, reddit, available at www.reddit.com, and digg, available at www.digg.com, offer slightly finer grained yet still relatively large topic categories with vetting by a single user community. Opening critical review to individual or small user communities increases impartiality and, therefore, user confidence in authoritativeness, but the similar lack of fine-grained topic organization prevents customized discovery of new relevant information. The northwest quadrant approaches are also limited to single user communities, as typified by the “techie-gamer” communities that frequent the Redditt and Digg Web sites, or, like the Topix Web site, have multiple communities, but do not have fine-grained topic coverage or diverse subject areas. Still, other approaches exist, such as Daylife, which has more topics than typical news Web sites, yet does not organize information into hierarchical topical indexes with fine-grained topics. Moreover, the site is not organized into communities with members and their indexes, nor can users define new communities. 
     In contrast to the foregoing conventional approaches, the approach described herein uses: (1) index training and extrapolation to enable the right-end of the x-axis, and (2) voting in multiple augmented communities to enable the top-end of the y-axis. The social indexing system  73  uniquely occupies the northeast quadrant by providing fine-grained topical organization  63  through evergreen indexes  49  in conjunction with vetting by multiple user communities  65 . The social part refers to the human element in the process. This organizational approach and community-based vetting ensures that each user receives both relevant and authoritative information from both his home and select neighboring communities. 
     Evergreen Index Overview 
     An evergreen index identifies and relates materials along expert-chosen topical joints, which reflect the expert&#39;s point of view on behalf of his augmented community as to material that is important. An evergreen index embodies judgments of how people in the augmented community will use the information cited and reflects a subject matter expert&#39;s articulation of important topics and references to where the topics are discussed. 
     The division of information into fine-grained categories enables several capabilities, including providing the capability to segregate article votes into fine-grained topic groups, rather than just one or a few large subject area groups. This capability also enables the estimating of article quality on a fine grain, and provides meaningful comparison of articles within a topic. Absent this capability, the utility of voting is mainly for determining “most popular” stories. Long tail stories, that is, stories of narrow interest, essentially disappear from view. Another benefit of hierarchical topic organizations makes possible the ability to associate user-editable “wiki-like” commentary with each topic in a community. This ability provides a place for community discussion and summarization of each topic. 
     An evergreen index is created through supervised machine learning and applied by index extrapolation, 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.  FIG. 6  is a data flow diagram showing an overview of evergreen index training. In brief, an evergreen index  88  is formed by pairing a topic or subtopic  89  with a topic model  90 . The evergreen index  88  is trained by starting with a training index  81 , which can be either a conventional index, such as for a book or hyperlinks to Web pages, or an existing evergreen index. For each index entry  82 , seed words  84  are selected (operation  83 ) from the set of topics and subtopics in the training index  81 . Candidate topic models  86 , such as patterns, are generated (operation  85 ) from the seed words  84 . The topic models transform direct page citations, such as found in a conventional index, into an expression that can be used to test whether a given text is on topic. Topic models can be specified as patterns as well as term vectors or any other form of testable expression. Finally, the candidate topic models  86  are evaluated (operation  87 ) against positive and negative training sets  91 ,  92 . As the candidate topic models  86  are generated in order of increasing complexity and decreasing probability, the best candidate topic models  86  are usually generated first. By favoring simple or low complexity candidate topic models  86 , the topic model evaluator follows the philosophy of Occam&#39;s razor to choose the simplest candidate topic models  86  that explain the data. Considerations of structural complexity are also helpful to avoid over-fitting in machine learning, especially when the training data is sparse. 
     The automatic categorization of new digital information using an evergreen index is a continual process. The topic models  90  in an evergreen index  88  enable new and relevant digital information to be automatically categorized by topic  89  through index extrapolation. Unlike a conventional index, an evergreen index  88  contains topic models  89  instead of citations, which enables the evergreen index  88  to function as a dynamic structure that is both untied to specific digital information and applicable over any digital information. New pages, articles, or other forms of digital information are identified, either automatically, such as through a Web crawler, or manually by the augmented community or others. The pages are matched against the topic models  90  of an evergreen index  88  to determine the topics or subtopics  89 , which best fit the information. Not every document will find a correctly matching topic model  90 . Some information may be wrongly matched, while other information may not be matched at all, yet still be worthy of addition to the evergreen index  88  as a new topic or subtopic  89 . 
     Information Frontiers 
     Augmented communities can be arranged as a social network that expresses relationships among those communities within the network who are interested in related subject matter.  FIG. 7  is a block diagram showing, by way of example, neighborhoods  100  of augmented communities. The neighboring augmented communities represent other fields of subject matter and groups of individuals sharing a common information interest. 
     Although each augmented community has its own evergreen index that focuses on a core subject matter, those augmented communities that focus on similar subject matter are topically related and appear closer on the information frontier of a home augmented community. For example, residents of a particular city, such as Palo Alto, Calif., could form an augmented community by creating their own evergreen index  103  to focus on newsworthy events concerning their city. Several cities and localities adjoin Palo Alto, including Stanford University, Menlo Park, East Palo Alto, and Mountain View. Their respective evergreen indexes  104   a - d  are topically related to the Palo Alto augmented community&#39;s evergreen index  103  and, by virtue of representing cities and localities physically adjacent to Palo Alto, collectively characterize an information frontier. 
     The selection of frontier augmented communities can be biased to favor those frontier communities that lie closer to the informational boundary of an augmented community. For example, Sunnyvale, Calif., is the next city south of Mountain View, so Sunnyvale&#39;s evergreen index  105  is at the closest edge of Mountain View&#39;s information frontier, yet is one degree of separation further from Palo Alto&#39;s information frontier. Thus, frontier information from closer frontier communities, such as Stanford University, would be favored as more closely related over the frontier information originating from more distant communities, like Sunnyvale. 
     In addition, the common behaviors of multiple frontier augmented communities could indirectly influence how frontier information is selected by a home augmented community. For instance, similarly strong ratings on articles about county taxation issues in the Menlo Park, East Palo Alto, and Mountain View communities could signal a topic of likely importance to the members of the Palo Alto augmented community. Thus, frontier information from frontier communities that has been selected through similar behaviors, such as strong and positive vetting, could be favored. 
     Together, Palo Alto, Stanford University, Menlo Park, East Palo Alto, Mountain View, and Sunnyvale form a social network  101   a , which is topically related by local news of interest to mid-Peninsula Bay Area residents. These augmented communities commonly define reflective information frontiers at the community level. On a broader scale, other social networks  101   b - d , respectively concerning wider ranging topics, such as medicine, baseball, and motorcycles, could also be within the universe of augmented communities and could more granularly define information frontiers at the individual community member level. More topically distant or even topically unrelated social networks  102   a - b  may also occupy the augmented community universe. These social networks  102   a - b  represent potential information frontiers where they play no active role in relating their respective core subject matter to the evergreen indexes of other social networks  101   a - d  or, more particularly, augmented communities  103 ,  104   a - d ,  105 . 
     Digital Information Prospecting 
     An augmented community does not exist in a vacuum to the exclusion of all other augmented communities. Rather, an augmented community coexists with a social network of communities, some of which are more closely aligned with the augmented community&#39;s core interests, others that are not. Accordingly, digital information prospecting focuses on finding topically related augmented communities and leveraging their vetting of similar subject matter to the benefit of a home augmented community.  FIG. 8  is a data flow diagram showing a method  120  for prospecting digital information in accordance with one embodiment. The method  120  is performed as a series of process steps by a server or other computing device. 
     An augmented community serves a social group whose members focus their collective attention on one or more core topics. Within the social network formed by related augmented communities, an individual&#39;s home augmented community  121  is characterized by an evergreen index  123 , which lists those topics and subtopics  124  reflecting the community&#39;s core interests. Each frontier augmented community  122  is characterized by an evergreen index  127  of topics and subtopics  128  reflecting that community&#39;s core interests. 
     Each augmented community  121 ,  122  accesses an information source  125 ,  129 , such as Web sites and feeds, and carves out an area of their own core interests through the topical models inherent in their respective evergreen indexes  123 ,  127 . The evergreen indexes  123 ,  127  are populated through digital information discovery (operation  131   a - b ), 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. Interrelatedness and overlapping of topical interests occurs along the informational boundaries of each augmented community, which constitutes an information frontier for a particular community. 
     Each augmented community  121 ,  122  vets information cited from the sources  125 ,  129  by voting within the topic or subtopic  124 ,  128  to which the information has been assigned and the top articles  126 ,  130  are thereby collectively determined. Information prospecting starts by first identifying frontier communities (operation  132 ), as further described below with reference to  FIG. 9 . A home augmented community  121  then capitalizes on the “the light work of the many” or “the wisdom of crowds” by determining the degree of interest afforded to frontier information in the frontier community&#39;s evergreen index  127 , as further described below with reference to  FIG. 10 . The top articles  126 ,  130  are then shared by relating the frontier information with the home augmented community&#39;s own list of topics and subtopics  124  (operation  134 ), as further described below with reference to  FIG. 11 . Other operations are possible. 
     Identifying Frontier Augmented Communities 
     Frontier information is considered important to an augmented community under the premise that members could benefit by becoming aware of related articles in other augmented communities. Initially, the frontier communities must be found.  FIG. 9  is a flow diagram showing a routine  140  for identifying frontier augmented communities for use with the method  120  of  FIG. 8 . Frontier communities can be identified through manual selection (block  141 ) by knowledge domain experts, that is, the leaders of a home augmented community who are responsible for sheparding the topics of an evergreen index. Those augmented communities that the leaders deem to bear sufficient relatedness to a community&#39;s core interests are identified and explicitly connected as belonging on the community&#39;s information frontier. 
     Alternatively, frontier communities can be automatically selected by generating similarity measures (block  142 ) and suggesting candidate neighbor communities from among those communities exhibiting the strongest similarity (block  143 ). Similarly measures reflect potential overlap in the respective core interests of the communities within a social network. Overlap could be suggested by reliance on the same information sources or feeds, citation to the same articles, or the use of comparable topic models in their respective evergreen indexes. The similarity measures can be quantitative values reflecting concrete degrees of similarity or dissimilarity, quality measures evaluated along a continuum, or a combination of indicia. Candidate neighboring communities can be picked by applying the similarity measures against a minimum threshold, taking a fixed number of high rated candidate communities, or through similar selection process. 
     Determining Degree of Interest 
     The importance assigned by a frontier community to the information referenced in the community&#39;s evergreen index is a good indicator of an augmented community&#39;s likely receptivity to the same information.  FIG. 10  is a flow diagram showing a routine  150  for determining degree of interest for use with the method  120  of  FIG. 8 . The frontier community first determines the importance of information cited into their evergreen index (block  151 ), which generally occurs through vetting, as described supra. The level of interest in a frontier community is used to select important new articles. In a further embodiment, the harvesting of frontier articles can be limited to certain parts of a topical taxonomy. The frontier community&#39;s ratings identify relevant articles and provide a preliminary estimate of degree of interest in the articles from the augmented community&#39;s evergreen index. 
     Next, attention across competing frontiers is allocated (block  152 ). The degree of separation from the frontier community is used to allocate attention across a set of frontier communities. In other words, stories arrive from multiple frontier communities. In the simplest approach, equal weight could be given to all frontiers. Alternatively, more attention could be afforded to some frontier communities over other frontiers by applying weighting. For instance, a distance metric could be determined to weigh the similarity of the frontier community to the augmented community, such as by observing the number of degrees of separation within the social network. 
     At this point, a set of articles and their topics from one or more frontiers have been selected and the articles need to be integrated into the home community Each topic of relevance is determined (block  153 ) by matching the articles against the patterns in the home communities. Where articles match no topics in a home community, articles are placed in a “news from the frontier” category with temporary subtopics borrowed from the frontiers. In a further embodiment, an augmented community leader could manually review the non-matching frontier information for potential consideration by the community, such as supplementing the topic models. 
     Relating Frontier Information 
     Information prospecting relies on the expertise of a frontier community to source and initially rate information. However, the augmented community&#39;s evergreen index is used to organize presentation of the information prospected.  FIG. 11  is a flow diagram showing a routine  160  for relating frontier information for use with the method  120  of  FIG. 8 . Few articles from a frontier community will have universal appeal in an augmented community. Thus, the augmented community&#39;s evergreen index is used to automatically classify articles by the topics and subtopics matched (block  161 ). Thereafter, the matched articles are routed to the community&#39;s members according to their respective topics of interest and the frontier articles are vetted along with the regular information indexed into the home index (block  162 ). As members read the articles in their core topics, highly rated frontier articles on the same topic compete with home articles for display space. Poorly rated frontier information will receive less positive response, while highly rated frontier information will remain, thus widening the scope of the augmented community in line with new ideas or emerging trends. 
     User Interface 
     Information discovery in social indexing is the combination of index extrapolation with topic-delimited voting. Voting personifies the “light work of the many.” Fine-grained categorization is crucial to voting because the categorization accounts for the assessment of the articles under each topic. Categorization ascertains which articles are the best and most worthy of the reader&#39;s attention. Voting is provided through a user interface that puts a face onto the evergreen index. 
     Web browsers have become a ubiquitous and widely-adopted information provisioning interface, which provides an ideal, although non-exclusive, platform for spatially presenting new and relevant digital information.  FIG. 12  is a screen shot diagram showing, by way of example, a user interface  180  providing digital information, including frontier information, organized by degree of interest. The user interface  180  brings together the two aspects of an information diet, relevancy and degree of interest, with voting. The user interface  180  provides an illustrative presentation, but other interfacing methodologies are equally possible. 
     The ratings of digital information voted by each augmented community can be provided on individual Web pages indexed by tabs  181  or other markers. Within each augmented community&#39;s tab, the topics and subtopics  182  of that augmented community can be listed first, with larger fonts or more prominent display attributes highlighting the most popular documents. The topics and subtopics  182  are selected from the augmented community&#39;s evergreen index and the documents are identified by matching a corpus of digital information against the topic models in the evergreen index, which can include digital information prospected from frontier communities, as described supra. 
     Degree of interest (DOI) refers to a numeric measure that is derived and intended to reflect how interesting some information will be. DOI can be determined relative to a particular article on a given topic, and can also be computed to relate a secondary topic to a primary one. DOI can be tailored to an individual based on information specific to the individual&#39;s history or state. When available, DOI can be used to optimize the presentation of information so that information with the highest DOI is favored, such as by giving the information more space or prominence. For instance, the highest ranked pages  183  can be allocated the largest amount of space with graphics, title, information regarding the source of the article, and abstract all provided. Other information or forms of visual or display emphasis could also be provided. Similarly, less highly rated pages  184  can be allocated less space, no graphics, and use smaller font sizes. Finally, lowest rated pages  185  can be relegated to the bottom of the tab with only the source and title of the page provided. Summarizations of the numbers of overall pages  186  can also be included as a convenience. 
     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.