Home > Articles

This chapter is from the book

Data and Metadata: The Resource-Centric View

Metadata is not only "about data"—it is also always data, itself. One person's data is another person's metadata. There is, in general, no difference between data and metadata; it's all a matter of perspective.

It is normal to think of metadata as being somehow "in orbit" around the data about which the metadata provides information. The existence of a metadata Web site that provides information about data Web sites affects global knowledge interchange in two ways.

  1. When users are at the metadata Web site, their attention can be directed at one or more data Web sites, and users can know the reasons why.

  2. When users are at the data Web site, they may derive more useful information if they also know about the availability of the metadata Web site and its reasons for expressing metadata about that data.

The idea that metadata can be externally and arbitrarily associated with data is a powerful one, but, by itself, this attractive and simple idea leads nowhere. When a single data Web site is associated with (that is, pointed at by) millions of metadata Web sites, the result can easily be "infoglut"—such a tidal wave of information that, as a practical matter, its overall utility is zero. There needs to be a way to use computers to determine the relevance of all this information to the user's specific situation and to show the relevant information while hiding the rest.

It is ironic that the recent huge improvement that information technology has brought to the accessibility of information—such as providing instant hyperlink traversal to any Web site, anywhere in the world—has itself made more and more information inaccessible due to the sheer quantity of it. The dream of global knowledge interchange recedes, even as it becomes real. Our power to filter out unwanted information must keep pace with the quantity of unwanted information. It's a race that we currently appear to be losing.

Although it may sound strange, it is imperative that we develop technical, economic, and business models that will allow businesses to make money by hiding information—by providing information that can be used to hide other information. It's also imperative that these models absolutely support and cherish diversity. This is because particular information filtration problems may, as a purely practical matter, require hiding information that emanates from a variety of sources and that reflects a variety of worldviews. These diverse sources may not even know about each other, much less deliberately design their products in such a way as to make them "federable" (that is, usable in concert) with one another. This is what the topic maps paradigm is all about: making diverse metadata sources more or less automatically federable.

One of the things that a metadata Web site may usefully provide is information as to which other Web sites have information on specific topics. Such metadata Web sites are often (and misleadingly) called search engines. But search engines do not usually provide topically organized information. Yahoo! is one notable exception, but it works only for a small number of topics and only in ways that are consistent with Yahoo!'s singular and necessarily self-serving view of the wide world of information. Instead, unlike Yahoo!'s topically oriented features, most search engines merely provide information about which other Web sites provide information that contains certain strings of characters. A user interested in information on a particular topic must be clever enough and lucky enough to be able to sneak up on relevant information on the basis of strings that he or she hopes will be found in such information—and not found in too much other information. The user must guess the language of the desired Web sites' information well enough to imagine which strings are relevant.

When a user attempts to find information, the user usually has a particular topic in mind about which he or she wishes to know more. The user is not interested in Web sites or specific information resources, except insofar as they offer information that is specifically relevant to that topic. The first order of business, then, really should be to allow the user and the computer to agree about exactly what topic the user wants to research. Once the computer has established the exact topic, the computer's task should be to hide all the information about the topic that, for one reason or another, the user should not be bothered with and to render only the remaining information. This kind of user interaction with the Web is supportable if topic maps are widely used because the topic maps paradigm explicitly permits and supports business models based on the development and exploitation of lists of topics that have names and occurrences in multiple languages for use in multiple contexts and that can themselves be found on the basis of their relationships with many other findable topics.

Still, there is an unbounded number of topics, there is an awful lot of information out there, and the sheer quantity is growing at a phenomenal rate. Many individual pieces of information can often be regarded as being relevant to many different topics simultaneously. Nobody will ever categorize everything, but many people will categorize some of it many times over, often in different and even conflicting ways.13 The topic maps paradigm explicitly permits and supports business models that are based on the development and exploitation of categorizations of information resources. Every category can be represented as a topic. Similarly, every system of categorization can also be represented as a topic. In fact, there is nothing that can't be represented as a topic. The exploitation of preexisting categorizations is not only the key to hiding unwanted information; it's also the key to finding it in the first place, unless it happens to contain some string that you are lucky enough to guess and that doesn't also appear in more than a few other resources.

Metametadata, Metametametadata . . .

One way to federate metadata is to create metadata about the metadata. Then, of course, we may need to federate that metametadata with other metametadata, using metametametadata. The absurdity of this approach is obvious: there is little opportunity for benefit to be realized from standardization in a model that requires infinitely recursive metalevels. There must be a better way. And there is: the topic maps paradigm moves in the other direction by recognizing the existence of a single, implicit, underlying layer. It's the same underlying universe that is known in philosophical circles as Platonic forms14 (so named for Plato, the ancient Greek philosopher mentioned earlier).

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020