Context is everything

 

Connecting state and local government leaders

CIO Council looks to semantic interoperability to expand data sharing.

Why is it so hard to share information between government databases? One theory gaining ground in federal interoperability circles is that the language used to translate the information is missing a critical element: verbs.

Database designers, in their relentless efficiency, allotted precisely defined individual data fields to contain all the data. In large part, they jettisoned any information about how those fields related to one another and to the agency that kept the information in the first place. In other words, they ditched the verbs that tied all the data elements together.

And they will need those verbs to share the information within their databases, especially if they want to share data on an ad hoc basis, said Lucian Russell, who heads Expert Reasoning and Decisions.

Russell spoke at a conference on information sharing held earlier this month by the CIO Council's Semantic Interoperability Community of Practice (SiCOP).

Agencies want to share information with other agencies and, more important, avoid the drudgery of setting up individual point-to-point connections to do so.

This is where semantic interoperability comes in. Researchers such as Russell are developing tools and techniques that consider the meaning of data as a key to how it could be reused. If the data could somehow describe itself in a machine-readable way, it could be reused without human intervention.

'We're looking at a change in the way computing gets done, which is less information-centric and more knowledge-centric,' said Mills Davis, founder of consulting firm Project10x and author of a recent report on such semantic technologies, 'Semantic Wave 2008' (GCN.com/965).

'We've always put logic into programming.

But now, the representation of what we think we know ' and the rules about reasoning about it ' is being put into data structures, so a lot of different programs can actually access and play with these things,' Davis said.

Although the idea of semantic interoperability might seem abstract, the February SiCOP meeting showed a few examples of how it can work and even how federal agencies are putting the idea into use.

Russell described the traditional way that database creation has been taught: The designer isolates the information that needs to be captured, then creates a schema that captures all the relationships among the data elements.

But once the database is created, the schema typically is not included with the data.

The downside here is that someone trying to understand the database later would have no way of deciphering what relationship all the elements have to one another.

'What is thrown out in the creation of a database schema is how a lot of this data is related,' Russell said.

Such knowledge can also be considered the context of the data, said Steve Ray, a chief of the manufacturing systems integration division at the National Institute of Standards and Technology, during a question-and-answer session at the conference. 'Context is nothing more than a collection of all the unstated assumptions you have. If you manage to get them all down, you're then context-free. You can then start talking about semantic interoperability.'

Russell advocated the development of data descriptors, which would define the relationship structure of databases, using the verbs database creators omitted.

'All this information has been destroyed,' he said. 'You're going to have to recreate it.'

With descriptors in place, work can then be done to make databases start to recognize one another's data. Selmer Bringsjord, a doctoral student at Rensselaer Polytechnic Institute, presented his doctoral work on what he called 'the database schema mismatch problem.'

Stock example Bringsjord gave an example: Three databases track the prices of stocks at the close of the market each day. One database may have one entry for every stock on each day. A second database may have one entry for every day, with each entry being the closing price for every stock. A third database has a table for each stock, and each entry contains the closing price and date for that table.

Although there is a relationship between these databases, he said, such a relationship would not be accessible through a single query rendered by the Structured Query Language, the standard language for relational databases.

One approach to querying multiple databases that researchers have formulated would be to use the Interoperable Database Language (IDL) to build a union of the databases, which each database could use to query the other two.

IDL could map where each data element could be placed in any of the databases.

However, Bringsjord took a different approach, which 'describe[s] what kind of information each system is tracking [and] how that information is structured.' Although this approach might not facilitate the ability to move all the information of one system into another, it does allow one system to query another, even if the datasets of the two systems are incompatible, Bringsjord said.

His approach is to devise bridging axioms that extend the database schemas until they arrive at a common language. If one database tracks maternal relationships, such as Person A is the mother of Person B, an additional axiom could chart a new entity, grandmother, which would be a compound of the mother element.

A mother of another mother would be a grandmother.

'The goal is to travel from one ontology to another one, where at each step we have a bridging axiom,' Bringsjord said.

Using Slate, a tool that helps in the analytical process (GCN.com/964), Bringsjord described how an intelligence analyst could ask if someone participated in a terrorism- related event, such as a bombing. Although the analyst has no information on that particular individual, he does have information on other participants in the bombing and can search the relationships between those individuals documented in other information systems.

Not everyone's databases will have the same terminology, but there are tools that will help find multiple terms that might describe the same thing or identify similar terms.

One tool Russell said could help is WordNet, an English lexical database developed by Princeton University's Cognitive Science Laboratory (GCN.com/962). Partially funded by the National Science Foundation and the Defense Advanced Research Projects Agency, WordNet links words together, offering synonyms, troponyms and other relations for each word searched.

Also potentially useful would be Cyc (GCN.com/963), which is a representational vocabulary, said Michael Witbrock, vice president of research at CycCorp., which oversees the development of Cyc. Like WordNet, Cyc contains hundreds of thousands of words, along with descriptions of how they are related.

'It is capable of representing things unambiguously,' Witbrock said.

Despite progress, the goal of semantic interoperability among information technology systems remains far off.

NIST's Ray said 'there are a number of fundamental science questions that have to be answered before the engineering can be done on top of things such as semantic interoperability.'

For instance: How do you measure the semantic distance between two concepts? 'We don't have a unit of measurement for that.'

One semantic program that the Air Force and Army use is Revelytix's Knoodl, a combination ontology editor, registry/repository and wiki.

Brooke Stevenson, president at Army IT contractor Spry Enterprises, said the Army's Office of the Chief Information Officer is using Knoodl to establish a service-wide common vocabulary for Core Enterprise Services Domain, an effort to facilitate reuse of Army IT systems.

Knoodl is an online service that allows different parties to set up their own communities, said Michael Lang, co-founder of Revelytix. In the Army's community, the CIO office defined the basic subject areas, such as security, collaboration and networking, Stevenson said.

'The way the Army is currently approaching this is to only define a template for what these services should be,' Stevenson said. 'It's not going to be just top down, but also bottom up. We'll define the minimal amount of information that we'll need in order to make those types of services reusable.'

NEXT STORY: Tubes for the 21st century

X
This website uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners. Learn More / Do Not Sell My Personal Information
Accept Cookies
X
Cookie Preferences Cookie List

Do Not Sell My Personal Information

When you visit our website, we store cookies on your browser to collect information. The information collected might relate to you, your preferences or your device, and is mostly used to make the site work as you expect it to and to provide a more personalized web experience. However, you can choose not to allow certain types of cookies, which may impact your experience of the site and the services we are able to offer. Click on the different category headings to find out more and change our default settings according to your preference. You cannot opt-out of our First Party Strictly Necessary Cookies as they are deployed in order to ensure the proper functioning of our website (such as prompting the cookie banner and remembering your settings, to log into your account, to redirect you when you log out, etc.). For more information about the First and Third Party Cookies used please follow this link.

Allow All Cookies

Manage Consent Preferences

Strictly Necessary Cookies - Always Active

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data, Targeting & Social Media Cookies

Under the California Consumer Privacy Act, you have the right to opt-out of the sale of your personal information to third parties. These cookies collect information for analytics and to personalize your experience with targeted ads. You may exercise your right to opt out of the sale of personal information by using this toggle switch. If you opt out we will not be able to offer you personalised ads and will not hand over your personal information to any third parties. Additionally, you may contact our legal department for further clarification about your rights as a California consumer by using this Exercise My Rights link

If you have enabled privacy controls on your browser (such as a plugin), we have to take that as a valid request to opt-out. Therefore we would not be able to track your activity through the web. This may affect our ability to personalize ads according to your preferences.

Targeting cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

Social media cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks. They are capable of tracking your browser across other sites and building up a profile of your interests. This may impact the content and messages you see on other websites you visit. If you do not allow these cookies you may not be able to use or see these sharing tools.

If you want to opt out of all of our lead reports and lists, please submit a privacy request at our Do Not Sell page.

Save Settings
Cookie Preferences Cookie List

Cookie List

A cookie is a small piece of data (text file) that a website – when visited by a user – asks your browser to store on your device in order to remember information about you, such as your language preference or login information. Those cookies are set by us and called first-party cookies. We also use third-party cookies – which are cookies from a domain different than the domain of the website you are visiting – for our advertising and marketing efforts. More specifically, we use cookies and other tracking technologies for the following purposes:

Strictly Necessary Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Functional Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Performance Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Social Media Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Targeting Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.