Making Local Knowldge Globally Useful

Wisdom of Crowds

In his book, The Wisdom of Crowds, James Suroweicki says that to effectively harness the collective intelligence of a crowd, there needs to be the right balance between

Two Fundamental Principles of Information Design

Surowiecki's observations lead directly to two information design principles:

  1. Design information to be resolutely specific and local.
  2. Design information to be globally and collectively useful.

Information that is Local and Specific

Consider a Web designer that embeds a family name in an HTML <li> element, e.g.,


A second Web designer embeds a family name in an HTML <div> element, e.g.,


A third Web designer embeds a family name in an XML element, e.g.,


A fourth Web designer embeds a family name in an XML element, e.g.,


A fifth Web designer embeds a family name in an RSS element, e.g.,


Each of these Web designers are expressing the family name information in a way that is resolutely specific and local, i.e., in a way that is appropriate for his/her specific needs and requirements

However, the information is not globally and collectively useful, i.e., without a-priori knowledge a general Web tool cannot ascertain that the information within the elements represents a person's family name. That's where Microformats come into the picture.

Making Information Globally Useful

Add the hCard "family-name" subproperty to each local expression:

<li class="family-name">Costello</li>

<div class="family-name">Novak<div>

<informant class="family-name">Smith</informant>

<pilot class="family-name">Johnson</pilot>

<managingEditor class="family-name">Parker</managingEditor>

Now the information is resolutely specific and local; simultaneously it is globally and collectively useful.

Resolving Name Collisions

Consider a product manufacturer that releases a list of their products "by family" and marks up their content with the class "family-name", how is it distinguished from the hCard Microformat family-name subproproperty?

There are two ways:

First, the family-name is embedded within an element with class="vcard", e.g.,

<div class="vcard">
    <div class="family-name">Novak</div>

Thus, the context can identify that family-name refers to the hCard family-name subproperty, and not some other family-name.

Second, the hCard profile URL indicates that "within this document is an hCard Microformat", e.g.,

<html xmlns="" xml:lang="en" lang="en">
    <head profile="">
        <div class="vcard">
            <div class="family-name">Novak</div>

Now there are two indications that family-name represents an hCard family-name subproperty.