Home' Technology Review : July August 2009 Contents FROM THE EDITOR
TECHNOLOGY REVIEW JULY/AUGUST
FROM THE EDITOR
Search engines are knowledge systems that we ask, "What is
known?" The answers we get reflect the questions the sys-
tems' designers allow, which in turn reflect designers' concep-
tions of what is knowable and useful to know.
The first search engines were not machines, and they didn't sat-
isfy their users. The most famous of them all, the Oracle of Apollo
at Delphi on the slopes of Mount Parnassus, issued prophecies
for more than a thousand years. We possess more than 500 of the
results of queries put to the Pythia, the priestess who presided
over the Oracle. With exceptions, her answers were not helpful.
King Croesus of Lydia once asked the Oracle if he should wage
war on the Persians, whose empire was expanding westward
after a successful revolt against their rulers, the Medes. Accord-
ing to the historian Herodotus, the Pythia answered that if he
did, he would destroy a great empire. Cautious, Croesus sent
a large fee to the Delphians, and refined his search terms. He
pressed: Would his reign be a long one? The answer, according to
my battered Penguin translation by A. R. Burn, came back:
"When comes the day that a mule shall sit on the Median throne,
then, tender-footed Lydian, by pebbly Hermus run and abide not, nor
think it shame to be a coward."
Opaque---but Herodotus writes, "This reply gave Croesus more
pleasure than anything he had yet heard; for he did not sup-
pose that a mule was likely to become king of the Medes, and
that meant that he and his line would remain in power forever."
Alert readers will have guessed the end. Croesus went to war; the
empire he destroyed was his own. Cyrus, the king of the Persians,
was half Persian and half Mede, and thus a kind of mule.
The answers of the Delphic Oracle abound in these sorts
of tricky occlusions. Whoever designed the system at Delphi
believed or pretended to believe that the future was known to the
god Apollo, who chose (as a demonstration of the mutability of
human a airs) to deliver through his priestesses prophecies that
were obscure, but that retrospectively provided dramatic satisfac-
tion. A rationalist will suspect that obscure answers had another
function: they could apply equally well to di erent outcomes. In
any case, the turbidity of the Oracle's answers was its virtue.
In this month's cover story ("Search Me," p. 32), Technology
Review's chief correspondent, David Talbot, describes how the
Web is usually searched: "Among all the leaders in Web search ...
the core approach has remained the same. They create massive
indexes of the Web---that is, their software continually 'crawls'
the Web, collecting phrases, keywords, titles, and links." Talbot
examines some of the technical limitations of this method. But
the notion that a search should produce a list of links to Web
pages represents a view of what is knowable and what is useful to
know that is as specific as that which made the Delphic Oracle.
Traditional search is chaotically democratic. It assumes that the
consensus view is the best, while rewarding the wayward answer
by exposing it to the curious. The truths of traditional search are
provisional. Popularity is virtue.
Our story describes a new kind of search engine, Wolfram
Alpha. In fact, its inventor, the physicist and entrepreneur Ste-
phen Wolfram, dislikes the word search: he calls it a "compu-
tational knowledge engine." Alpha, writes Talbot, is "meant to
compute answers rather than list Web pages." It consists of "three
elements ... a constantly expanding collection of data sets, an
elaborate calculator, and a natural-language interface for queries."
Alpha, too, represents a particular point of view---that of its cre-
ator. Wolfram's monumental book, A New Kind of Science (2002),
explains how the complex world can be reduced to simple rules,
and how those rules are computable. Alpha will be the first major
application of his theories: an experiment to see how much of
what is known can be expressed in straightforward answers.
About these fundamental questions, views di er. Ivan Herman
of the World Wide Web Consortium tells Talbot, "Although I have
graduated as a mathematician ... I am not sure you can handle all
of the miseries of this world by mathematical formula and com-
putation." Another critic provides an example: "Imagine a ques-
tion like 'Who are the most dangerous terrorists?' ... Is someone
a terrorist? How do we assess danger? And danger to whom? It's
computationally very di cult to do that kind of reasoning."
Perhaps, speculates Daniel Tunkelang, the cofounder of the
search company Endeca, there is a better way to approach the
problem of building a search engine (see "To Search, Ask," p. 13).
"What we need is human-computer information retrieval. ...
Rather than guessing what users need, these tools provide users
with opportunities to clarify and elaborate their intent. If the
engine isn't sure what users want, it just asks them."
Now there's an alternative that is somehow shocking: Ask the
questioner. Write and tell me what you think at jason.pontin@
technologyreview.com. ---Jason Pontin
FOUR KINDS OF SEARCH ENGINES
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