#Head of the Natural Language Group at USC/ISI (University of Southern
California / Information Sciences Institute)
The Natural Language Group (NLG) at the Information Sciences Institute of the
University of Southern California (USC/ISI) is currently involved in various
aspects of computational/natural language processing. The group's projects are:
machine translation; automated text summarization; multilingual verb access and
text management; development of large concept taxonomies (ontologies); discourse
and text generation; construction of large lexicons for various languages; and
multimedia communication.
Eduard Hovy, his director, is a member of the Computer Science Departments of
USC and of the University of Waterloo. He completed a Ph.D. in Computer Science
(Artificial Intelligence) at Yale University in 1987. His research focuses on
machine translation, automated text summarization, text planning and generation,
and the semi-automated construction of large lexicons and terminology banks. The
Natural Language Group at ISI currently has projects in most of these areas.
Dr. Hovy is the author or editor of four books and over 100 technical articles.
He currently serves as the President of the Association of Machine Translation
in the Americas (AMTA). He is Vice President of the Association for
Computational Linguistics (ACL), and has served on the editorial boards of
Computational Linguistics and the Journal of the Society of Natural Language
Processing of Japan.
*Interview of August 27, 1998
= How do you see the growth of a multilingual Web?
In the context of information retrieval (IR) and automated text summarization
(SUM), multilingualism on the Web is another complexifying factor. People will
write their own language for several reasons -- convenience, secrecy, and local
applicability -- but that does not mean that other people are not interested in
reading what they have to say! This is especially true for companies involved in
technology watch (say, a computer company that wants to know, daily, all the
Japanese newspaper and other articles that pertain to what they make) or some
government intelligence agencies (the people who provide the most up-to-date
information for use by your government officials in making policy, etc.). One of
the main problems faced by these kinds of people is the flood of information, so
they tend to hire "weak" bilinguals who can rapidly scan incoming text and throw
out what is not relevant, giving the relevant stuff to professional translators.
Obviously, a combination of SUM and MT (machine translation) will help here;
since MT is slow, it helps if you can do SUM in the foreign language, and then
just do a quick and dirty MT on the result, allowing either a human or an
automated IR-based text classifier to decide whether to keep or reject the
article.
For these kinds of reasons, the US Government has over the past five years been
funding research in MT, SUM, and IR, and is interested in starting a new program
of research in Multilingual IR. This way you will be able to one day open
Netscape or Explorer or the like, type in your query in (say) English, and have
the engine return texts in all the languages of the world. You will have them
clustered by subarea, summarized by cluster, and the foreign summaries
translated, all the kinds of things that you would like to have.
You can see a demo of our version of this capability, using English as the user
language and a collection of approx. 5,000 texts of English, Japanese, Arabic,
Spanish, and Indonesian, by visiting MuST (Multilingual information retrieval,
summarization, and translation system).
Type your query word (say, "baby", or whatever you wish) in and press
Enter/Return. In the middle window you will see the headlines (or just keywords,
translated) of the retrieved documents. On the left you will see what language
they are in: "Sp" for Spanish, "Id" for Indonesian, etc. Click on the number at
left of each line to see the document in the bottom window. Click on "Summarize"
to get a summary. Click on 'Translate' for a translation (but beware: Arabic and
Japanese are extremely slow! Try Indonesian for a quick word-by-word
"translation" instead).
This is not a product (yet); we have lots of research to do in order to improve
the quality of each step. But it shows you the kind of direction we are heading
in.
= How do you see the future?
The Internet is, as I see it, a fantastic gift to humanity. It is, as one of my
graduate students recently said, the next step in the evolution of information
access. A long time ago, information was transmitted orally only; you had to be
face-to-face with the speaker. With the invention of writing, the time barrier
broke down -- you can still read Seneca and Moses. With the invention of the
printing press, the access barrier was overcome -- now anyone with money to buy
a book can read Seneca and Moses. And today, information access becomes almost
instantaneous, globally; you can read Seneca and Moses from your computer,
without even knowing who they are or how to find out what they wrote; simply
open AltaVista and search for "Seneca". This is a phenomenal leap in the
development of connections between people and cultures. Look how today's
Internet kids are incorporating the Web in their lives.
The next step? -- I imagine it will be a combination of computer and cellular
phone, allowing you as an individual to be connected to the Web wherever you
are. All your diary, phone lists, grocery lists, homework, current reading,
bills, communications, etc., plus AltaVista and the others, all accessible (by
voice and small screen) via a small thing carried in your purse or on your belt.
That means that the barrier between personal information (your phone lists and
diary) and non-personal information (Seneca and Moses) will be overcome, so that
you can get to both types anytime. I would love to have something that tells me,
when next I am at a conference and someone steps up, smiling to say hello, who
this person is, where last I met him/her, and what we said then!
But that is the future. Today, the Web has made big changes in the way I shop (I
spent 20 minutes looking for plane routes for my next trip with a difficult
transition on the Web, instead of waiting for my secretary to ask the travel
agent, which takes a day). I look for information on anything I want to know
about, instead of having to make a trip to the library and look through
complicated indexes. I send e-mail to you about this question, at a time that is
convenient for me, rather than your having to make a phone appointment and then
us talking for 15 minutes. And so on.
*Interview of August 8, 1999
= What has happened since our first interview?
Over the past 12 months I have been contacted by a surprising number of new
information technology (IT) companies and startups. Most of them plan to offer
some variant of electronic commerce (online shopping, bartering, information
gathering, etc.). Given the rather poor performance of current non-research
level natural language processing technology (when is the last time you actually
easily and accurately found a correct answer to a question to the Web, without
having to spend too much time sifting through irrelevant information?), this is
a bit surprising. But I think everyone feels that the new developments in
automated text summarization, question analysis, and so on, are going to make a
significant difference. I hope so!--but the level of performance is not
available yet.
It seems to me that we will not get a big breakthrough, but we will get a
somewhat acceptable level of performance, and then see slow but sure incremental
improvement. The reason is that it is very hard to make your computer really
"understand" what you mean--this requires us to build into the computer a
network of "concepts" and their interrelationships that (at some level) mirror
those in your own mind, at least in the subjects areas of interest. The surface
(word) level is not adequate -- when you type in "capital of Switzerland",
current systems have no way of knowing whether you mean "capital city" or
"financial capital". Yet the vast majority of people would choose the former
reading, based on phrasing and on knowledge about what kinds of things one is
likely to ask the Web, and in what way.
Several projects are now building, or proposing to build, such large "concept"
networks. This is not something one can do in two years, and not something that
has a correct result. We have to develop both the network and the techniques for
building it semi-automatically and self-adaptively. This is a big challenge.
= What do you think about the debate concerning copyright on the Web? What
practical solutions would you suggest?
As an academic, I am of course one of the parasites of society, and hence all in
favor of free access to all information. But as a part-owner of a small startup
company, I am aware of how much it costs to assemble and format information, and
the need to charge somehow.
To balance these two wishes, I like the model by which raw information (and some
"raw" resources, such as programming languages and basic access capabilities
like the Web search engines) are made available for free. This creates a market
and allows people to do at least something. But processed information, and the
systems that help you get and structure just exactly what you need, I think
should be paid for. That allows developers of new and better technology to be
rewarded for their effort.
Take an example: a dictionary, today, is not free. Dictionary companies refuse
to make them available to research groups and others for free, arguing that they
have centuries of work invested. (I have had several discussions with dictionary
companies on this.) But dictionaries today are stupid products -- you have to
know the word before you can find the word! I would love to have something that
allows me to give an approximate meaning, or perhaps a sentence or two with a
gap where I want the word I am looking for, or even the equivalent in another
language, and returns the word(s) I am looking for. This is not hard to build,
but you need the core dictionary to start with. I think we should have the core
dictionary freely available, and pay for the engine (or the service) that allows
you to enter partial or only somewhat accurate information and helps you find
the best result.
A second example: you should have free access to all the Web, and to basic
search engines like those available today. No copyrights, no license fees. But
if you want an engine that provides a good targeted answer, pinpointed and
evaluated for trustworthiness, then I think it is not unreasonable to pay for
that.
Naturally, an encyclopedia builder will not like my proposal. But to him or her
I say: package your encyclopedia inside a useful access system, because without
it the raw information you provide is just more data, and can easily get lost in
the sea of data available and growing every hour.
*Interview of September 2, 2000
= What has happened since our last interview?
I see a continued increase in small companies using language technology in one
way or another: either to provide search, or translation, or reports, or some
other communication function. The number of niches in which language technology
can be applied continues to surprise me: from stock reports and updates to
business-to-business communications to marketing...
With regard to research, the main breakthrough I see was led by a colleague at
ISI (I am proud to say), Kevin Knight. A team of scientists and students last
summer at Johns Hopkins University in Maryland developed a faster and otherwise
improved version of a method originally developed (and kept proprietary) by IBM
about 12 years ago. This method allows one to create a machine translation (MT)
system automatically, as long as one gives it enough bilingual text. Essentially
the method finds all correspondences in words and word positions across the two
languages and then builds up large tables of rules for what gets translated to
what, and how it is phrased.
Although the output quality is still low -- no-one would consider this a final
product, and no-one would use the translated output as is -- the team built a
(low-quality) Chinese-to-English MT system in 24 hours. That is a phenomenal
feat -- this has never been done before. (Of course, say the critics: you need
something like 3 million sentence pairs, which you can only get from the
parliaments of Canada, Hong Kong, or other bilingual countries; and of course,
they say, the quality is low. But the fact is that more bilingual and
semi-equivalent text is becoming available online every day, and the quality
will keep improving to at least the current levels of MT engines built by hand.
Of that I am certain.)
Other developments are less spectacular. There's a steady improvement in the
performance of systems that can decide whether an ambiguous word such as "bat"
means "flying mammal" or "sports tool" or "to hit"; there is solid work on
cross-language information retrieval (which you will soon see in being able to
find Chinese and French documents on the Web even though you type in
English-only queries), and there is some rather rapid development of systems
that answer simple questions automatically (rather like the popular web system
AskJeeves, but this time done by computers, not humans). These systems refer to
a large collection of text to find "factiods" (not opinions or causes or chains
of events) in response to questions such as "what is the capital of Uganda?" or
"how old is President Clinton?" or "who invented the xerox process?", and they
do so rather better than I had expected.
= What do you think about e-books?
E-books, to me, are a non-starter. More even that seeing a concert live or a
film at a cinema, I like the physical experience holding a book in my lap and
enjoying its smell and feel and heft. Concerts on TV, films on TV, and e-books
lose some of the experience; and with books particularly it is a loss I do not
want to accept. After all, it's much easier and cheaper to get a book in my own
purview than a concert or cinema. So I wish the e-book makers well, but I am
happy with paper. And I don't think I will end up in the minority anytime soon
-- I am much less afraid of books vanishing than I once was of cinemas
vanishing.
= What is your definition of cyberspace?
I define cyberspace as the totality of information that we can access via the
Internet and computer systems in general. It is not, of course, a space, and it
has interesting differences with libraries. For example, soon my fridge, my car,
and I myself will be "known" to cyberspace, and anyone with the appropriate
access permission (and interest) will be able to find out what exactly I have in
my fridge and how fast my car is going (and how long before it needs new shock
absorbers) and what I am looking at now. In fact, I expect that advertisements
will change their language and perhaps even pictures and layout to suit my
knowledge and tastes as I walk by, simply by recognizing that "here comes
someone who speaks primarily English and lives in Los Angeles and makes $X per
year". All this behaviour will be made possible by the dynamically updatable
nature of cyberspace (in contrast to a library), and the fact that computer
chips are still shrinking in size and in price. So just as today I walk around
in "socialspace" -- a web of social norms, expectation, and laws -- tomorrow I
will be walking around in an additional cyberspace of information that will
support me (sometimes) and restrict me (other times) and delight me (I hope
often) and frustrate me (I am sure).
= And your definition of the information society?
An information society is one in which people in general are aware of the
importance of information as a commodity, and attach a price to it as a matter
of course. Throughout history, some people have always understood how important
information is, for their own benefit. But when the majority of society starts
working with and on information per se, then the society can be called an
information society. This may sound a bit vacuous or circularly defined, but I
bet you that anthropologists can go and count what percentage of society was
dedicated to information processing as a commodity in each society. Where they
initially will find only teachers, rulers' councillors, and sages, they will in
later societies find people like librarians, retired domain experts
(consultants), and so on. The jumps in communication of information from oral to
written to printed to electronic every time widened (in time and space)
information dissemination, thereby making it less and less necessary to re-learn
and re-do certain difficult things. In an ultimate information society, I
suppose, you would state your goal and then the information agencies (both the
cyberspace agents and the human experts) would conspire to bring you the means
to achieve it, or to achieve it for you, minimizing the amount of work you'd
have to do to only that is truly new or truly needs to be re-done with the
material at hand.