Posted:May 21, 2013

Neighbourhoods of Winnipeg - NOWFirst and Largest Local Government Site to Exclusively Embrace Semantic Technologies

The City of Winnipeg, the capital and largest city of Manitoba, Canada, just released its “NOW” portal celebrating its diverse and historical 236 neighborhoods. The NOW portal is one of the largest releases of open data by a local government to date, with some 57 varied datasets now available ranging from local neighborhood amenities such as pools and recreation centers, to detailed real estate and economic development information. Nearly one-half million individual Web pages comprise the site, driven exclusively by semantic technologies. Nearly 10 million RDF triples underly the site.

In announcing the site, Winnipeg Mayor Sam Katz said, “We want to attract new investment to the city and, at the same time, ensure that Winnipeg remains healthy and viable for existing businesses to thrive and grow.” He added, “The new web portal, Neighbourhoods of Winnipeg—or NOW—is one way that we are making it easy to do business within the City of Winnipeg.”

NOW provides a single point of access for information such as location of schools and libraries, Census and demographic information, historical data and mapping information. A new Economic Development feature included in the portal was developed in partnership with Economic Development Winnipeg Inc. (EDW) and Winnipeg REALTORS®.

Our company, Structured Dynamics, was the lead contractor for the effort. An intro to the technical details powering the Winnipeg site is provided in the complementary blog post by SD’s chief technologist, Fred Giasson. These intro announcements by SD will be later followed by more detailed discussions on relevant NOW portal topics in the coming weeks.

Background and Formal Release

But the NOW story is really one of municipal innovation and a demonstration of what a staff of city employees can accomplish when given the right tools and frameworks. SD’s real pleasure over the past two years of development and data conversion for this site has been our role as consultants and advisors as the City itself converted the data and worked the tools. The City of Winnipeg NOW (Neighbourhoods of Winnipeg) site is testament to the ability of semantic technologies to be learned and effectively used and deployed by subject matter professionals from any venue.

In announcing the site on May 13, Mayor Sam Katz also released a short four-minute introductory video about the site:

What we find most exciting about this site is how our open source Open Semantic Framework can be adopted to cutting-edge municipal open data and community-oriented portals. Without any semantic technology background at the start of the project, the City has demonstrated its ability to manage, master and then tailor the OSF framework to its specific purposes.

Key Emphases

As its name implies, the entire thrust of the Winnipeg portal is on its varied and historical neighborhoods. The NOW portal itself is divided into seven major site sections with 2,245 static pages and a further 425,000 record-oriented pages. The number of dynamic pages that may be generated from the site given various filtering or slicing-and-dicing choices is essentially infinite.

Neighborhoods

The fulcrum around which all data is organized on the NOW portal are the 236 neighborhoods within the City of Winnipeg, organized into 14 community areas, 15 political wards, and 23 neighborhood clusters. These neighborhood references link to thousands of City of Winnipeg and external sites, as well as have many descriptive pages of their own.

Some 57 different datasets contribute the information to the site, some authored specifically for the NOW portal with others migrated from legacy City databases. Coverage ranges from parks, schools, recreational and sports facilities, and zoning, to libraries, bus routes, police stations, day care facilities, community gardens and more. More than 1,400 attributes characterize this data, all of which may be used for filtering or slicing the data.

Property and Economic Development

A key aspect of the site is its real estate, assessment and zoning information. Every address and parcel in the city — a count nearing 190,000 in the current portal — may be looked up and related to its local and neighborhood amenities. Up to three areas of the City may be mapped and compared to one another, felt to be a useful tool for screening economic development potentials.

Census Data

All of the neighborhood and neighborhood clusters may be investigated and compared for Census data in two time periods (2001 and 2006). Types of Census informaton includes population, education, labor and work, transportation, education, languages, income, minorities and immigration, religion, marital status, and other family and household measures.

Any and all neighborhoods may be compared to one another on any or all of these measures, with results available in chart, table or export form.

Images and History

Images and history pages are provided for each Winnipeg neighborhood.

Mapping

Throughout, there are rich mapping options that can be sliced and displayed on any of these dimensions of locality or type of information or attribute.

More to Come!

The basic dataset authoring framework will enable City staff (and, perhaps, external parties or citizens) to add additional datasets to the portal over time.

Key Functionality and Statistics

The NOW site is rich in functionality and display and visualization options. Some of this functionality includes the:

NOW Ontology Graph

NOW Graph Structure

NOW is entirely an ontology-driven site, with both domain and administrative ontologies guiding all aspects of search, retrieval and organization. There are 12 domain ontologies govering the site, two of which are specific to NOW (the NOW ontology and a Canadian Census ontology). Ten external ontologies (such as FOAF, GeoNames, etc) are also used.

The NOW ontology, shown to the left, has more than 2500 subject concepts within it covering all aspects of municipal governance and specific Winnipeg factors.

Relation Browser

All of the 2500 linked concepts in the NOW ontology graph can be interactively explored and navigated via the relation browser. The central “bubble” also presents related, linked information such as images, Census data, descriptive material and the like. As adjacent “bubbles” are clicked, the user can navigate or “swim through” the NOW graph.

NOW Relation Browser

NOW Web Maps

Web Map

Nearly all of the information on the NOW site — or about 420,000 records — contains geolocational information of one form or another. There are about 200,000 points of interest records, another 200,000 area or polygon records, and about 7,000 paths and routes such as bus routes in the system.

All 190,000 property addresses in Winnipeg may be looked up and mapped.

Virtually all of the 57 datasets in the system may be filtered by category or type or attribute. This information can be filtered or searched using about 1400 different facets, singly or in combination with one another.

Various map perspectives are provided from facilities (schools, parks, etc.) to economic development and history, transportation routes and bus stops, and property, real estate and zoning records.

Templates

Depending on the type of object at hand, one of more than 50 templates may be invoked to govern the display of its record information. These templates are selected contextually from the ontology and present different layouts of map, image, record attribute or other information, all keyed by the governing type.

Each template is thus geared to present relevant information for the type of object at hand, in a layout specific to that object.

Objects lacking their own specific templates default to the display type of their parent or grandparent objects such that no object type lacks a display format.

Multiple templates are displayed on search pages, depending upon the diversity of object types returned by the given search.

Example of a NOW Record Template

Example of a NOW Census Chart

Graph Statistics

The NOW site provides a rich set of Census statistics by neighborhood or community area for comparison purposes. The nearly half million data points may be compared between neighborhoods (make sure and pick more than one) in graph form (shown) or in tabular form (not shown).

Census information spans from demographics and income to health, schooling and other measures of community well-being.

Like all other displays, the selected results can also be exported as open data (see below).

Image Gallery

The NOW portal presently has about 2700 images on site organized by object type, neighborhood, and historical. These images are contextually available in multiple locations throughout the site.

The History topic section also matches these images to historical neighborhood narratives.

Example of a NOW Image Gallery

Example conStruct Tool: structOntology

conStruct Tools

A series of twenty or so back office tools are available to City of Winnipeg staff to grow, manage and otherwise maintain the portal. Some of these tools are exposed in read-only form to the general public (see Geeky Tools next).

The example at left is the structOntology tool for managing the various ontologies on the site.

Geeky Tools

As a means to show what happens behind the scenes, the Geeky Tools section presents a number of the back office tools in read-only form. These are also good ways to see the semantic technologies in action.

The Geeky Tools section provides access to Search, Browse, Ontology, and Export (see next) tools.

NOW's Geeky Tools

The NOW Export Function

Open Data Exports

On virtually any display or after any filter selection, there is an “export” button that allows the active data to be exported in a variety of formats. Under Geeky Tools it is also possible to export whole datasets or slices of them. Some of the key formats include:

Some of these are serializations that are not standard ones for RDF, but follow a notation that retains the unique RDF aspects.

Some Early Lessons

Though the technical aspects of the NOW site have been ready for quite some time, with limited staff and budget it took City staff some time to convert all of its starting datasets and to learn how to develop and manage the site on its own. As a result, some of the design decisions made a couple of years back now appear a bit dated.

For example, the host content management system is Drupal 6, though Drupal 8 is getting close to its own release. Similarly, some of the display widgets are based on Flash, which Adobe announced last year it will continue to maintain, but will no longer develop. In the two years since design decisions were originally made, the importance of mobile apps and smartphones and tablets has also grown tremendously in importance.

These kinds of upgrades are a constant in the technology world, and apply to NOW as well. Fortunately, the underlying basis of the entire portal in its data and stack were architected to enable eventual upgrades.

Another key aspect of the site will be the degree to which external parties contribute additional data. It would be nice, for example, to see the site incorporate events announcements and non-City information on commercial and non-profit services and facilities.

Conclusion

Structured Dynamics is proud about the suitability of our OSF technology stack and is impressed with all the data that is being exposed. Our informal surveys suggest this is the largest open data portal by a major city worldwide to be released to date. It is certainly the first to be powered exclusively by semantic technologies.

Yet, despite those impressive claims, we submit that the real achievement of this project is something different. The fact that this entire portal is fully maintained and operated by the City’s own internal IT staff is a game changer. The IT staff of the City of Winnipeg had no prior internal semantic Web knowledge, nor any knowledge in RDF, OWL or any other underlying technologies used by the portal. What they had is a vision of their project and what they wanted. They placed significant faith and made a commitment to master the OSF technology stack, and the underlying semantic Web concepts and principles to make their vision a reality. Much of SD’s 430+ documents on the OSF TechWiki are a result of this collaborative technology transfer between us and the City.

We are truly grateful that the City of Winnipeg has taken open source and open data quite seriously. In our partnership wth them they have been extremely supportive of what we have done to progress the technology, release it as open source, and then to document our lessons and experiences for other parties to utilize as documented on the TechWiki. The City of Winnipeg truly shows enlightened government at its best. Thank you, especially to our project managers, Kelly Goldstrand and Don Conolly.

Structured Dynamics has long stated its philosophy as, “We are successful when we are no longer needed. We’re extremely pleased and proud that the NOW portal and the City of Winnipeg show this objective is within realistic reach.

Posted:February 18, 2013

The Semantic Enterprise Part 6 in the Enterprise-scale Semantic Systems Series

The fulcrum by which semantic technologies work within the enterprise is the dataset. A dataset refers to a named grouping of records, best designed as similar in record types and intended access rights (though technically a dataset is any named grouping of records).

Datasets play a central role in the organization of information in Structured Dynamics‘ (SD) open semantic framework (OSF). Datasets are one of the three major access dimensions to the OSF (the other two being users/groups and tools/endpoints). In combination, these three dimensions — datasets, users/groups and tools/endpoints — can also result in a powerful set of profiles that govern overall access to content.

Specific security aspects of the semantic enterprise stack are discussed in another part of this Enterprise-scale Semantic Systems (ESSS) series, but the interplay of those aspects with datasets is fundamental. As such, how datasets are bounded and organized (and, then, named) is a critical management consideration for enterprises that adopt a semantic technology stack based on an architecture like OSF. This role of datasets, how to organize them, how to manage them, and also some best practices for how to use them, are the focus of this part in our series.

Access Dimensions to the OSF

To briefly recall the architectural discussion in this series, SD’s semantic technology stack involves a Web services layer (structWSF) used to access specific functional endpoints, all via HTTP queries [1]. Some of these endpoints access complete applications in such areas as tagging, imports/exports, search and the like. Other endpoints individually provide (or not) access to CRUD (createread- updatedelete) rights to interact with either individual records, full datasets, or the ontologies that are the “schema” overlying this information. The net result, at present, is more than 20 individual Web service endpoints to query and interact with the system:

Web ServiceCreateReadUpdateDelete
Auth Registrar: AccessXX  
Auth Registrar: WSXX  
Auth: Lister X  
Auth: Validator X  
Ontology: CreateX   
Ontology: Read X  
Ontology: Update  X 
Ontology: Delete   X
Dataset: CreateX   
Dataset: Read X  
Dataset: Update  X 
Dataset: Delete   X
CRUD: CreateX   
CRUD: Read X  
CRUD: Update  X 
CRUD: Delete   X
Search X  
SPARQL X  
Tracker: CreateX   
Scones    

This structWSF Web services layer has a three-dimensional design that is used to govern access:

  1. Users (or Groups or Roles)
  2. Tools, and
  3. Datasets.

A “user” may extend from an individual to an entire class or group of users, say, unregistered visitors to a given portal. Tools refer to each of the structWSF endpoints, each with its own URI.

What this means is that a given user may be granted access or not — and various rights or not from reading to the creation or deletion of information — in relation to specific datasets. Stated another way, it is in the nexus of user type and dataset that access control is established for the semantic system.

In an enterprise context, a given individual (“user”) may have different access rights depending on circumstance. A worker in a department may be able to see and do different things for departmental information than for enterprise information. A manager may be able to view budget information that is not readable by support personnel. A visitor to a different Web site or portal may see different information than visitors to other Web sites. Supervisors might be able to see and modify salary data for certain employees that is not viewable by others.

The user role or persona thus becomes the access identifier to the system. What information and what tools they might use in relation to that information is defined in relation to the datasets for which they have access.

Some Access Scenarios

So, let’s say, a given enterprise has two major information stores, #1 and #2, and also has some domain (or departmental or other such boundary) information for X, Y and Z, some of which is local (perhaps for the local branch) and the rest global (for that line of business). Further, let’s also suppose that those same departments also have sensitive, internal information related to either internal matters (such as salaries) or support matters (such as qualified vendors). This basic scenario is laid out in A of the diagram below:

Now, depending, different individuals (most often assigned to different access groups, but that is not required) need to have different access to this information. In one case, a general user with access to mostly public stuff exists for domain B; another for domain C. Then still, a supervisor or someone internally may have responsibilities in the Y domain; that could be case D.

Any of the same variations above could result in a different use case; AD above is merely illustrative.

Profiles to Overcome the Combinatorial Problem

It is fairly easy to see that the combination of datasets x tools x roles can lead to many access permutations. With, say, the current 20 some-odd tools in the OSF with five different roles and just ten different datasets, we already have about 1,000 permutations. As portals and dataset numbers grow, this combinatorial explosion gets even worse. Of course, not all combinations of datasets, tools and roles make sense. In fact, only a relatively few number of patterns likely covers 95% or more of all likely access options.

Because access rights are highly patterned, these theoretical combinations can in fact be boiled down to a small number of practical templates — called profiles — to which a newly registered dataset can be assigned. (Of course, the enterprise could also tweak any of the standard profiles to meet any of the combinatorial options for a specific, unusual individual, such as for a tax auditor.)  Experience, in fact, shows the number of actual profiles to be surprisingly small.

For instance, consider these possible profile patterns:

  • Profile: Public (standard) — this profile is for a dataset intended for broad public access
  • Profile: Registered — this profile is for datasets that are limited to registered users of a portal (possibly as a way to prevent spam or to encourage membership or participation)
  • Profile: Curated — this profile is where a specific group or groups (which themselves can be flexibly determined and assigned) has curation rights for the dataset, or
  • Profile: Internal — this profile is for internal (private) datasets where only a specific group or groups may access or modify. In some instances, an internal dataset might be the profile type while the dataset is under development, with the profile shifting to a broader access category once completed.

Profiles may, of course, be applied to any permutation.

This profile concept can now be expanded to incorporate user type. Four categories of users can illustrate this dimension:

  • O = Owner (the original registrar of the dataset; often possibly the “owner” or “admin” of the portal, but not necessarily so)
  • G = Group member (a registered user who is a member of a specific group)
  • R = Registered user (an authorized portal user with a Drupal login and password)
  • P = Public (anonymous user)

Further, of course, with a multitude of groups, there are potentially many more than four categories (“roles”) of users as well.

A Sample Profile Matrix

To illustrate how we can collapse this combinatorial space into something more manageable, let’s look at what one of the profile cases noted above — that is the Public profile — can now be expressed as a pattern or template. In this example, the Public profile means that owners and some groups may curate the data, but everyone can see and access the data. Also note that export is a special case, which could warrant a sub-profile.

We also need to relate this Public profile to a specific dataset. For this dataset, we can characterize our “possible” assignments as described above as to whether a specific user category (O, G, R and P as noted above) has available a given function (open dot), gets permission rights to that function by virtue of the assigned profile (solid dot), or whether that function may also be limited to a specific group or groups (half-filled dot) or not.

Thus, we can now see this example profile matrix for the Public profile for an example dataset with respect to the available structWSF Web services:

Note, of course, that these options and categories and assignments are purely arbitrary for our illustrative discussion. Actual needs and circumstances may vary wildly from this example.

Matrices such as this seem complex, but that is why profiles can collapse and simplify the potential assignments into a manageable number of discrete options. If the pre-packaged profiles need to be tweaked or adjusted for a particular circumstance, provisions through the CMS enables all assignments to be accessed in individual detail. Via this design, knowledge and collaboration networks can be deployed that support an unlimited number of configurations and options, all in a scalable, Web-accessible manner. The data that is accessed is automatically expressed as linked data. This same framework can be layered over in situ existing data assets to provide data federation and interoperable functionality, all responsive to standard enterprise concerns regarding data access, rights and permissions.

Best Practices

Datasets are clearly one of the fundamental dimensions for organizing content within this OSF semantic enterprise design. Some of the best practices in bounding these structures:

  • Domain – what is the applicable scope or business purpose of this information? It is best to think of this question with regard to access, which is, after all, the most pragmatic way to think of it
  • Source – does the data vary by publisher or source location? For example, provenance or download location or format may be an important distinguishing factor in release or access, and may have copyright or royalty implications
  • When created – does the data have periodic update or creation times? For example, it may be important to distinguish between preliminary data and final data or to segregate data because of workflow or processing considerations
  • Access rights – are there any differences in how users may see or act upon the data? For example, privileged budget information may be put in a different dataset from public financial information
  • Type – does the data vary by class or kind? For example, records about schools might be desirable to keep different from records about churches, though at a different level both may be considered buildings, or
  • Attributes – are there differences in fields or attributes that describe the data? For example, a portion of records may have complete attribute descriptions, while the majority only contain a few descriptive fields.

Any of these differences may warrant creating a separate dataset. There are no limits to the number of datasets that may be managed by a given OSF instance.

Once such boundaries get set, then thinking about common attributes or metadata should be applied. Still further, datasets and their records (as all decision or information artifacts in an enterprise) go through natural work stages or progressions. Even the lowliest written document needs to be drafted, reviewed, characterized, approved, and then possibly revised. Whatever such workflow steps may be, including versioning, may warrant consideration as belonging to a different dataset.

Lastly, whatever the operational mode devised, finding naming conventions to reflect these variations is essential to manage the dataset files. Which goes to show: datasets are meaningful information artifacts in and of themselves.

NOTE: This is part of an ongoing series on enterprise-scale semantic systems (ESSS), which has its own category on this blog. Simply click on that category link to see other articles in this series.

[1] Or programmatically via the structWSF API.
Posted:February 11, 2013

The Semantic Enterprise Part 5 in the Enterprise-scale Semantic Systems Series

We become such captives to our language and what we think we are saying. Many basic words or concepts, such as “search,” seem to fit into that mould. A weird thing with “search” is that twenty years ago the term and its prominence were quite different. Today, “search” is ubiquitous and for many its embodiment is Google such that “to google” is often the shorthand for “to search”.

When we actually do “search”, we submit a query. The same extension that has inveigled its tendrils into search has also caused the idea of a query to become synonymous with standard text (Google) search.

But, there’s more, much more, both within the meaning and the execution of “to search”.

Enterprises, familiar with structured query language (SQL), have understood for quite some time that queries and search were more than text searches to search engines. Semantic technologies have their own structured query approach, SPARQL. Enterprises know the value of search from discovery to research and navigation. And, they also intuitively know that they waste much time and don’t often get what they want from search. U.S. businesses alone could derive $33 billion in annual benefits from being better able to re-find previously discovered Internet information, an amount equal to $10 million per firm for the 1,000 largest businesses [1]. And those benefits, of course are only for Internet searches. There are much larger costs arising from unnecessary duplicated effort because of weaknesses in internal search [1].

The thing that’s great about semantic search — done right — is it combines conventional text search with structured search, adds more goodies, and basically overcomes most current search limitations.

Many Kinds of Search

The Webster definition of “search” is to, look into or over carefully or thoroughly in an effort to find or discover something.”

There are two telling aspects to this definition. One, search may be either casual or careful, from “looking” into something to being “thorough”. Second, search may have as its purpose finding or discovery. Finding, again, implies purpose or research. Discovery can range from serendipity to broadening one’s understanding or horizons given a starting topic.

Prior to the relational systems, network databases represented the state-of-the-art. One of E.F. Codd‘s stated reasons in developing the relational approach and its accompanying SQL query language was to shift the orientation of databases from links and relationships (the network approach) to query and focused search [2]. By virtue of the technology design put forward, relational databases shifted the premise to structured information and direct search queries. Yet, as noted, this only represents the purposeful end of the search spectrum; navigation and discovery now becomes secondary.

Text search and (text) search engines then came to the fore, offering a still-different model of indexing and search. Each term became a basis for document retrieval, leading to term-based means of scoring (the famous Salton TF/IDF statistical model), but with actually no understanding of the semantic structure or meaning of the document. Other term-based retrieval bases, such as latent semantic indexing, were put forward, but these were based on the statistical relationships between terms in documents, and not the actual meaning of the text or natural language within the documents.

What we see in the early evolution of “search” is kind of a fragmented mess. Structured search swung from navigation to purposeful queries. Text search showed itself to be term-based and reliant on Boolean logic. Each approach and information store thus had its own way to represent or index the data and a different kind of search function to access it. Web search, with its renewal of links and relationships, further shifted the locus back to the network model.

State-of-the-art semantic search , as practiced by Structured Dynamics, has found a way to combine these various underlying retrieval engines with the descriptive power of the graph and semantic technologies to provide a universal search mechanism across all types of information stores. We describe this basis more fully below, but what is important to emphasize at the outset is that this approach fundamentally addresses all aspects of search within the enterprise. As a compelling rationale for trying and then adopting semantic technologies, semantic search is the primary first interest for most enterprises.

Unique Advantages to Semantic Search

The first advantage of semantic search is that all content within the organization can be combined and searched at once. Structured stuff . . . documents . . . image metadata . . . databases . . . can now all be characterized and put on an equivalent search footing. As we just discussed in text as a first class citizen, this power of indexing all content types is the real dynamo underneath semantic search.

The universality of search means that being able to search all available content is awesome. But, being able to add the dimensions of relationships between things means that the semantic graph takes information exploration to a totally new level.

The simplest way to understand semantic search is to de-construct the basic RDF triple down to its fundamentals. This first tells us that the RDF data model is able to represent any thing, that is, an object or idea. And, we can represent that object in virtually any way that any viewer would care to describe it, in any language. Do we want it to be big, small? blue, green? meaningful, silly? smart, stupid? The data model allows this and more. We can capture how diverse users describe the same thing in diverse ways.

But, now that I have my world populated with things and descriptions of them, how do they connect? What are the relationships between these things? It is the linkages — the connections, the relationships — between things that give us context, the basis for classifying, and as a result, the means to ascertain the similarity or adjacency of those things. These sorts of adjacencies then enable us to understand the “pattern” of the thing, which is ultimately the real basis for organizing our world.

The rich brew of things (‘nouns”) and the connections between them (“verbs”) starts to give our computers a basis for describing the world more akin to our real language. It is not perfect, and even if it were, it would still suffer from the communication challenges that occur between all of us as humans. Language itself is another codified way of transmitting messages, which will always suffer some degree of loss [3]. But in this comment we can also glean a truth: humans interacting with their computer servants will be more effective the more “human” their interfaces are. And this truth can also give us some insight into what search must do.

First, we are interested in classifying and organizing things. The idea of “facets”, the arrangement of search results into categories based on indexed terms, is not a new one in search. In conventional approaches, “facets” are approached as a kind of dimension, one that is purposefully organized, sometimes hierarchically. In Web interfaces, facets most often appear as a listing in a left-hand column from which one or more of these dimensions might be selected, sometimes with a count number of potential results after the facet or sometimes with a checkbox or such by which multiple of these facets might be combined. In essence, these facets act as structural or classificatory “filters” for the content at hand. This is made potentially more powerful when also combined with basic keyword search.

In semantic search, facets may be derived from not only what types of things exist in the search space, but also what kinds of attributes (or properties) connect them. And, this all comes for free. Unlike conventional faceting, no one needs to decide what are the important “dimensions” or any such. With semantic search, the very basis of describing the domain at hand creates an organization of all things in the space.  As a result of semantic search, this combination of entities and properties leads to what could be called “global faceting”. The structure of how the domain is described is the sole basis required to gain — and make universal to the information space — these facets.

Whoa! How did that happen? All we did is describe our information space, but now we have all of this rich structure. This is when the first important enterprise realization sets in:  how we describe the information in our domain is the driving, critical factor. Semantic search is but easy pickings from this baseline. What is totally cool about the nature of semantic search is that slicing-and-dicing would put a sushi restaurant to shame. Every property represents a different pathway; and every entry (node) is an entry point.

Second, because we have based all of this on an underlying logic model in descriptive logics, we gain a huge Archimedes’ lever about our information space. We do not need to state all of the relationships and organizations in our information space. We can infer them from the assertions already made. Two parents have a child? That child has a sibling? Then, we can infer the second child also has the same parents. The “facts” that one might assume about a given domain can grow by 10x or more when inference is included.

Now we can begin to see where the benefits and return from semantic search becomes evident. Semantic search also enables a qualitatively different content enrichment: we can use these broad understandings of our content to do better targeting, tagging, highlighting or relating concepts to one another. The fact that semantic search is simply a foundation to semantic publishing is noteworthy. We will discuss this topic in a later part to this series.

SD’s Approach: RDF Triple Store + Solr + OWLAPI

In recognition of the primacy of search, we at Structured Dynamics were one of the first in the semantic Web community to add Solr (based on Lucene) full-text indexing to the structured search of an RDF triple store [4]. We later added the OWL API to gain even more power in our structured queries [5]. These three components give us the best of unstructured and structured search, and enable us to handle all kinds of search with additional flexibility at scale. Since we historically combined RDF and Solr first, let’s discuss it first.

We first adopted Solr because traditional text search of RDF triple stores is not sufficiently performant and makes it difficult to retrieve logical (user) labels in place of the URIs used in semantic technologies. While RDF and its graph model provide manifest benefits (see below), text search is a relatively mature technology and Solr provided commercial-grade features and performance in an open source option.

In our design, the triple store is the data orchestrator. The RDF data model and its triple store are used to populate the Solr schema index. The structural specifications (schema) in the triple store guide the development of facets and dynamic fields within Solr. These fields and facets in Solr give us the ability to gain Solr advantages such as aggregates, autocompletion, spell checkers and the like. We also are able to capture the full text if the item is a document, enabling standard text search to be combined with the structural aspects orchestrated from the RDF. On the RDF side, we can leverage the schema of the underlying ontologies to also do inferencing (via forward chaining). This combination gives us an optimal search platform to do full-text search, aggregates and filtering.

Since our initial adoption of Solr, and Solr’s own continued growth, we have been able to (more-or-less) seamlessly embrace geo-locational based search, time-based search, the use of multiple search profiles and ranking and scoring approaches (using Solr’s powerful extended disMax edismax parser) and other advantages. We now have nearly five years of experience of the RDF + Solr combination. We continue to discover new functionality and power in this combination. We are extremely pleased with this choice.

On the structured data side, RDF and its graph model have many inherent advantages, as earlier described. One of those advantages is the graph structure itself:

Example Taxonomy Structure Example Ontology Structure
A distinguishing characteristic of ontologies compared to conventional hierarchical structures is their degree
of connectedness, their ability to model coherent, linked relationships

Another advantage over conventional structured search (SQL) with relational databases is performance. For example, as Rik Van Bruggen recently explained [6], RDBMs searches that need to obtain information from more than one table require a “join.” The indexes in all applicable tables need to be scanned recursively to find all the data elements fitting the query criteria. Conversely, in a graph database, the index needs only be accessed once to find the starting point in the graph, after which the relationships in the graph are “walked” to traverse the graph to find the next applicable data elements. The need for complete scans is what makes “joins” expensive computationally. Graph queries are incredibly fast because index lookups are hugely reduced.

Queries that experienced DBAs with relational databases would never attempt because of the excessive need for joins are trivial in a graph search.

Various graph databases provide canned means for traversing or doing graph-based operations. And that brings us to the second addition we added to the RDF triple store: inclusion of the OWL API. While it is true that our standard triple store, Virtuoso, has support for simple inferencing and forward chaining, the fact that our semantic technologies are based on OWL 2 means that we can bring more power to bear with an ontology-specific API, including reasoners.The OWL API allows all or portions of the ontology specification to be manipulated separately, with a variety of serializations. Changes made to the ontology can also be tested for validity. Most leading reasoners can interact directly with the API. Protégé 4 also interacts directly with the API, as can various rules engines. Additionally, other existing APIs, notably the Alignment API with its own mapping tools and links to other tools such as S-Match can interact with the OWL API.

Thus, besides the advantages of RDF and graph-based search, we can now reason over and manipulate the ontologies themselves to bring even more search power to the system. Because of the existing integrations between the triple store and Solr, these same retrieval options can also be used to inform Solr query retrievals.

Shaking Hands with the Enterprise

On the face of it, a search infrastructure based on three components — triple store + Solr + OWL API — appears more complex than a single solution. But, enterprises already have search provided in many different guises involving text or SQL-based queries. Structured Dynamics now has nearly five years experience with this combined search configuration. Each deployment results in better installation and deployment procedures, including scripting and testing automation. The fact there are three components to the search stack is not really the challenge for enterprise adoption.

This combined approach to search really poses two classes of challenges to the enterprise. The first, and more fundamental one, is the new mindset that semantic search requires. Facets need to be understood and widely embraced; graphs and graph traversals are quite new concepts; full incorporation of tagging to make text a first-class citizen with structured search needs to be embraced; and, the pivotal role of ontologies in driving the whole structural understanding of the domain and all the various ways to describe it means a shift in thinking from dedicated applications for specific purposes to generic ontology-driven applications. These new mindsets require concerted knowledge transfer and training. Many of the new implementers are now the subject matter experts and content editors within the enterprise, rather than developers. Dedicated effort is also necessary — and needs to be continually applied — to enable ontologies to properly and adaptively capture the enterprise’s understanding of its applicable domain.

These are people-oriented aspects that require documentation, training materials, tools and work processes. These topics, actually some of the most critical to our own services, are discussed in later parts to this ESSS series.

The second challenge is in the greater variability and diversity of the “dials and knobs” now available to the enterprise to govern how these search capabilities actually work. The ranking of search results can now embrace many fields and attributes; many different types of content; and potentially different contexts. Weights (or “boosts” in Solr terms) can be applied to every single field involved in a search. Fields may be included or excluded in searches, thereby acting as filters. Different processors or parsers may be applied to handle such things as text case (upper or lower), stemming for dealing with plurals and variants, spelling variants such as between British and American English, invoking or not synonyms, handling multiple languages, and the like.

This level of control means that purposeful means and frameworks must be put in place that enable responsible managers in the enterprise to decide such settings. Understanding of these “dials and knobs” must therefore also be transferred to the enterprise. Then, easily used interfaces for changing and selecting options and then comparing the results of those changes must be embedded in tools and transferred. (This latter area is quite exciting and one area of innovation SD will be reporting on in the near future.)

The Productivity Benefits

There are actually many public Web sites that are doing fantastic and admirable jobs of bringing broad, complicated, structured search to users, all without much if any semantic technologies in the back end. Some quick examples that come to mind are Trulia in real estate; Fidelity in financial products; Amazon in general retail, etc. One difficulty that semantic search has in comparison to the alternatives is that first-blush inspection of Web sites may not show many large differences.

The real advantages from semantic search comes in its productivity and flexibility. Semantic search frameworks are easier to construct, easier to extend, easier to modify and cheaper to build. Semantic search frameworks are inherently robust. Adding entirely new domains of scope — say from moving from a department level to the entire enterprise or accommodating a new acquisition — can be implemented in a fraction of the time without the need for rework.

It will be necessary to document the use case experience of early adopting enterprises to quantify these productivity and flexibility benefits. From Structured Dynamics’ experience, however, these advantages are in the range of one to two orders of magnitude in reduced deployment and maintenance costs compared to RDBMs-based approaches.

The Tie-in with Semantic Publication

Another hot topic of late has been “semantic publishing” that is of keen interest to media and content-intensive sites on the Web. What is interesting about semantic pubishing, however, is that it is completely founded on semantic search. All of the presentation or publishing of content in the interface (or in an exported form) is the result of search. Remember, due to Structured Dynamics’ semantic technology design with its structWSF interfaces, all interaction with the underlying engines and system occur via queries.

We will be talking much about semantic publishing toward the conclusion of this series. We will cover content enrichment, new kinds of products such as topic pages and semantic forms and widgets, and the fact that semantic publishing is available almost for “free” when your stack is based on semantic technologies with semantic search, SD-style.

NOTE: This is part of an ongoing series on enterprise-scale semantic systems (ESSS), which has its own category on this blog. Simply click on that category link to see other articles in this series.

[1] M.K. Bergman, 2004. “Untapped Assets: The $3 Trillion Value of U.S. Enterprise Documents,” BrightPlanet Corporation White Paper, December 2004, 41 pp. Published on this blog at http://www.mkbergman.com/82/untapped-assets-the-3-trillion-value-of-us-enterprise-documents/.
[2] See, for instance, the Wikipedia entry on the historical development of databases.
[3] M.K. Bergman, 2012. “What is Structure?,” AI3:::Adaptive Information blog, May 28, 2012.
[4] F. Giasson, 2009. “RDF Aggregates and Full Text Search on Steroids with Solr,” Fred Giasson’s blog, April 9, 2009.
[5] M.K. Bergman, 2010. “A New Landscape in Ontology Development Tools,”, AI3:::Adaptive Information blog, September 7, 2010.
[6] See, for example, Rik Van Bruggen, 2013. “Demining the ‘Join Bomb’ with Graph Queries,” Neo4J blog, January 28, 2013.
Posted:January 28, 2013

The Semantic Enterprise Part 4 in the Enterprise-scale Semantic Systems Series

Text, text everywhere, but no information to link!

For at least a quarter of a century the amount of information within an enterprise embedded in text documents has been understood to be on the order of 80%; more recent estimates put that contribution at 90%. But, whatever the number, or no matter how you slice it, the percentage of information in documents has been overwhelming for enterprises.

The first documentation systems, Documentum being a notable pioneer, helped keep track of versions and characterized its document stores with some rather crude metadata. As document management systems evolved — and enterprise search became a go-to application in its own right — full-text indexing and search was added to characterize the document store. Search allowed better access and retrieval of those documents, but still kept documents as a separate information store from the true first citizens of information in enterprises — structured databases.

That is now changing — and fast. Particularly with semantic technologies, it is now possible to “tag” or characterize documents not only in terms of administrative and manually assigned tags, but with concepts and terminology appropriate to the enterprise domain.

Early systems tagged with taxonomies or thesauri of controlled vocabulary specific to the domain. Larger enterprises also often employ MDM (master data management) to help ensure that these vocabularies are germane across the enterprise. Yet, even still, such systems rarely interoperate with the enterprises’ structured data assets.

Semantic technologies offer a huge leverage point to bridge these gaps. Being able to incorporate text as a first-class citizen into the enterprise’s knowledge base is a major rationale for semantic technologies.

Explaining the Basis

Let’s start with a couple of semantic givens. First, as I have explained many times on this blog, ontologies — that is, knowledge graphs — can capture the rich relationships between things for any given domain. Second, this structure can be more fully expressed via expanded synonyms, acronyms, alternative terms, alternative spellings and misspellings, all in multiple languages, to describe the concepts and things represented in this graph (a construct we have called “semsets“.) That means that different people talking about the same thing with different terminology can communicate. This capability is an outcome from following SKOS-based best practices in ontology construction.

Then, we take these two semantic givens and stir in two further ingredients from NLP. We first prepare the unstructured document text with parsing and other standard text processing. These steps are also a precursor to search; they provide the means for natural language processing to obtain the “chunks” of information in documents as structured data. Then, using the ontologies with their expanded SKOS labels, we add the next ingredient of OBIE (ontology-based information extraction) to automatically “tag” candidate items in the source text.

Editors are presented these candidates to accept or not, plus to add others, in review interfaces as part of the workflow. The result is the final subject “tags” assignment. Because it is important to tag both subject concepts or named entities in the candidate text, Structured Dynamics calls this approach “scones“. We have reusable structures and common terminology and syntax (irON) as canonical representations of these objects.

Add Conventional Metadata

Of course, not all descriptive information you would want to assign to a document is only what it is about. Much other structural information describing the document goes beyond what it is about.

Some of this information relates to what the document is: its size, its format, its encoding. Some of this information relates to provenance: who wrote it? who published it? when? when was it revised? And, some of this information relates to other descriptive relationships: where to download it? a picture of it; other formats of it. Of course, any additional information useful to describe the document can be also tagged on at this point.

This latter category is quite familiar to enterprise information architects. These metadata characterizations have been what is common for standard document management systems reaching back for three decades or more now.

So, naturally, this information has proven the test of time and also must have a pathway for getting assigned to documents. What is different is that all of this information can now be linked into a coherent knowledge graph of the domain.

Some Interface and Workflow Considerations

What we are seeking is a framework and workflow that naturally allows all exisitng and new documents to be presented through a pipeline that extends from authoring and review to metadata assignments. This workflow and the user interface screens associated with it are the more difficult aspects of the challenge. It is relatively straightforward to configure and set up a tagger (though, of course, better accuracy and suitability of the candidate tags can speed overall processing time). Making final assignments for subject tags from the candidates and then ensuring all other metadata are properly assigned can be either eased or impeded by the actual workflows and interfaces.

The trick to such semi-automatic processes is to get these steps right. There are the needs for manual overrides when the suggested, candidate tags are not right. Sometimes new terms and semset entries are found when reviewing the processed documents; these need to be entered and then placed into the overall domain graph structure as discovered. The process of working through steps on the tag processing screens should be natural and logical. Some activities benefit from very focused, bespoke functionality, rather than calling up a complicated or comprehensive app.

In enterprise settings these steps need to be recorded, subject to reviews and approvals, and with auditing capabilities should anything go awry. This means there needs to be a workflow engine underneath the entire system, recording steps and approvals and enabling things to be picked up at any intermediate, suspended point. These support requirements tend to be unique to each enterprise; thus, an underlying workflow system that can be readily modified and tailored — perhaps through scripting or configuration interfaces — is favored. Since Drupal is our standard content and user interface framework, we tend to favor workflow engines like State Machine over more narrow, out-of-the-box setups such as the Workflow module.

These screens and workflows are not integral to the actual semantic framework that governs tagging, but are essential complements to it. It is but another example of how the semantic technologies in an enterprise need to be embedded and integrated into a non-semantic environment (see the prior architecture piece in this series).

But, Also Some Caveats

Yet, what we have described above is the technology and process of assigning structured information to documents so that they can interoperate with other data in the enterprise. Once linked into the domain’s knowledge graph and once characterized by the standard descriptive metadata, there is now the ability to search, slice, filter, navigate or discover text content just as if it were structured data. The semantic graph is the enabler of this integration.

Thus, the entire ability of this system to work derives from the graph structure itself. Creating, populating and maintaining these graph structures can be accomplished by users and subject matter experts from within the enterprise, but that requires new training and new skills. It is impossible to realize the benefits of semantic technologies without knowledgeable editors to maintain these structures. Because of its importance, a later part in this series deals directly with ontology management.

While ontology development and management are activities that do not require programming skills or any particular degrees, they do not happen by magic. Concepts need to be taught; tools need to be mastered; and responsibiilties need to be assigned and overseen to ensure the enterprise’s needs are being met. It is exciting to see text become a first-class information citizen in the enterprise, but like any purposeful human activity, success ultimately depends on the people involved.

NOTE: This is part of an ongoing series on enterprise-scale semantic systems (ESSS), which has its own category on this blog. Simply click on that category link to see other articles in this series.
Posted:January 20, 2013

The Semantic Enterprise Part 3 in the Enterprise-scale Semantic Systems Series

The interests of enterprise architects and semantic technologists do not align. An enterprise architect has the viewpoint of the enterprise and its full breadth of IT requirements, from security to access to content and maintainability (all of which needs to be justified to non-IT managers). The semantic technologist tends to view his entire world through the lens of semantic technologies.

If one is a resident within the semantic technology community, more often than not today’s assessment is that semantics have yet to be successful. If the deployment somehow does not have semantic technologies front and center, then it is largely invisible. The fact that semantic technologies are the core enablers from initiatives ranging from Siri to Pandora to Google and recommendation engines is not embraced and credited: the semantic contribution is hidden.

If one is an enterprise architect, the primacy of whether semantic technologies are in play or not is a non-issue. There are many piece parts to be fulfilled; the system and overall architecture are the concern, not any individual component. The architecture must be broken apart, with the assessment of the suitability of any individual component not based solely on its standalone capabilities, but also as part of an inter-operating whole.

Semantic technology has generally not penetrated well into the enterprise (though it sometimes has in some of the consumer plays as noted above) because its advocates (and, therefore, deployers) have not understood its role. Sometimes semantic technologies are visible, but, more often than not, they are not. The natural role of semantic technologies is in content and schema mediation, functions which reside generally at the repository level and not that of the user.

Two rending forces arise from the wrongful perception that somehow semantic technologies must be evident. The first dissonance is that semantic advocates are often indiscriminate in where they focus their advocacies. While semantic approaches can, theoretically, be applied from the user content management level to applications, these are neither the pain points nor the focus of enterprise architects. EAs are interested in semantic technologies for content integration and interoperability, as often evidenced by superior search, not other uses. The second dissonance is that, not recognizing its natural role, semantic technologists are not paying attention to making their capabilities inter-operable with the rest of the enterprise stack.

Actual enterprise deployments have a rhythm and hierarchy of scrutiny and decision-making. For semantics to become an integral contributor to enterprise solutions, it is important to recognize where this function can fit today. There should be no arrogance in this discussion whatsoever. Like a Galileo thermometer, it is important to find the natural resting point for semantic contributions . . . .

A Basic Architecture

As other discussions by Fred Giasson and I have put forward, the nature of our (Structured Dynamics) semantic stack, what we call the open semantic framework (OSF), has Drupal as its resident content management piece, with Virtuoso the RDF triple store, and many additional open source parts. Our TechWiki explains more of that in detail.

The OSF architecture, though, is generalized enough such that these two components, or any of the other open source pieces in the stack, could be swapped out for others. It is the Web service glue underneath OSF, SD’s structWSF framework, that is the real enabler of the entire semantic stack.

Yet when one is done with design of an enterprise architecture, the actual semantic portion (shown in green below) becomes itself a mere component, all embedded into the full suite of enterprise requirements. This illustrative architecture, generalized across clients, again uses Drupal as the content management framework, with the new service being hosted in the cloud:

We see that a security component now governs all interactions. Middleware has been inserted into the standard OSF stack (Drupal + semantic services) and now takes over the functions of logging, messenging, an enterprise service bus, security, and version control and data governance things. All of our hardware, network services, and Web servers are provided in the cloud. We also need to conform to existing content and data sources and the means to harvest or get updates from them.

The semantic component — OSF in our case — has in effect been surrounded by existing or external sources and services. The semantic management responsibility resides at the core of this architecture, thus making the content repository very important. But, in order for the repository to perform its work, it must interface with all of these existing and required systems. In order for semantics to make enterprise contributions, it must become, in effect, a “hidden” or “buried” service.

When targeting enterprise customers, this role for semantic technologies is a reality. For systems to be adopted, which is the first step to being effective, it is helpful to warmly embrace that your installation will be as much involved with interfaces and external sources and systems as much as semantics alone. Embracing this viewpoint means you are being adopted.

This reality does place a premium on a Web service architecture for the semantic stack. All endpoints can be communicated with via HTTP, and all endpoints have a common and published API. Each re-factoring stresses making the interfaces distinct and clean, and embracing common syntax and protocols for communicating with the endpoints.

The Natural Resting Place for Semantic Technologies

We can expand the green portion of the diagram above — the semantic components or what corresponds to OSF — and show them in more detail, as in the next architecture diagram below. We are now enumerating the Web services in the stack, and are showing the interaction with datasets (important for the security aspects, which a later installment of this series will address). The various engines that power the OSF stack are shown at bottom:

While it is true that the semantic components are “buried” within all portions of the enterprise stack, we can ease the integration challenge by narrowing the interface points to the non-semantic portions. At the top level, in the interaction with the content management framework (Drupal in our case), we have aggregated all Web service interface calls and made them available via a programmatic API via the structWSF PHP API. (Multiples of these can be developed if the programmatic interfaces need to be in languages other than PHP, such as Java.)

The structWSF API provides a consolidated point for writing endpoint calls and queries using PHP. This not only makes it more efficient for developing endpoint connectors (whose purpose is to enable Drupal methods and modules for interfacing with the repository), but also provides a common API and methods. Though it is possible to issue queries directly to any structWSF Web service endpoint, the structWSF API module is a faster and more consistent interface for doing so. This consolidation also means that developers interacting with the semantic components need only worry about the dedicated API module, and not the code or location in the more than 20 individual endpoints.

A similar philosophy is applied to narrowing the security interfaces. We treat security as a black box. Granting access and rights is proxied at the middleware layer. If these rights are granted, the query payload is presented to the Auth:Validator endpoint via a registered security gateway IP. The verification of the IP by Auth:Validator enables the query to be submitted, with a results set also returned via the same pathway.

Three design mindsets govern this architectural design. First, interface points are narrowed and standardized, generally with a formal API. Second, important external services are treated as “black boxes”; how they do their work is immaterial. Only vetted requests and calls approved at these other layers are able or authorized to access the services at the semantic layer. And, third, we are not trying to embrace non-semantic functionality at the semantic layer. These important services — but ancillary ones from a semantic standpoint — are understood as being out of scope to the semantic requirements. This design also makes it easier to “plug” the semantic components into other enterprise stack configurations with other non-semantic services from other sources or vendors.

Some Development Gaps and Imperatives

This design makes sense from a theoretical standpoint, but can pose problems in practice.

The first challenge is that our OSF approach is based on RESTful Web services, in a true Web-oriented architecture. Many of the non-semantic legacy components were originally designed for formal big WS-* approaches drawn from the SOAP perspective. Though most of these existing interfaces have evolved to embrace RESTful alternatives, these interfaces are not always as well tested and complete as the original WS-* ones. This relative immaturity can pose issues with respect to completeness of parameter or function support or inadequate testing.

A second challenge, also related to a RESTful Web service perspective, is the size of payloads in both query and results set objects. Long HTTP queries with many parameter requests and large results sets can be a problem to handle, especially in the security layer. In some cases, we have had to look at ways to minimize and package (consolidate) parameter options in order to make endpoint requests more efficient.

Encoding mismatches are a further challenge. It is generally best, for example, to adhere to a standard UTF-8 encoding via all semantic component interfaces. This requires attention and coordination on both sides of the interface.

The more fundamental challenge, however, is one of mindset. Effective interfaces require effective communications of the participating vendors across the boundary. The terminology, concepts, logic and open-world approach of semantic technologies are not easily communicated to nor immediately understood by traditional practitioners. The communications must be constantly worked in order to overcome past practices and embrace the flexibilities provided by semantic technologies.

The Mismatch is Not Long-term

But these challenges are more one of degree and practice than anything more fundamental. As semantic components get deployed in an enterprise stack, the benefits of faceting and the underlying structure become apparent. Such awareness propels further understanding and a willingness to learn more about underlying foundations. Ultimately, with a design emphasizing a relatively few, focused interfaces, semantic components can be effectively integrated within enterprise stacks.

The more telling lesson is the understanding of the natural role that semantic technologies play within enterprise-scale systems. Semantic technologies are the natural integration framework for federating and interoperating virtually any and all non-transaction information assets of the enterprise. That places semantic technologies at the core of the enterprise stack, even if it is not terribly evident to all users. The natural role for semantic technologies for the nearest term appears to be in repositories and for content integration.

NOTE: This is part of an ongoing series on enterprise-scale semantic systems (ESSS), which has its own category on this blog. Simply click on that category link to see other articles in this series.