Navigation Links
MIT: The advantage of ambiguity in language

CAMBRIDGE, Mass. -- Why did language evolve? While the answer might seem obvious as a way for individuals to exchange information linguists and other students of communication have debated this question for years. Many prominent linguists, including MIT's Noam Chomsky, have argued that language is, in fact, poorly designed for communication. Such a use, they say, is merely a byproduct of a system that probably evolved for other reasons perhaps for structuring our own private thoughts.

As evidence, these linguists point to the existence of ambiguity: In a system optimized for conveying information between a speaker and a listener, they argue, each word would have just one meaning, eliminating any chance of confusion or misunderstanding. Now, a group of MIT cognitive scientists has turned this idea on its head. In a new theory, they claim that ambiguity actually makes language more efficient, by allowing for the reuse of short, efficient sounds that listeners can easily disambiguate with the help of context.

"Various people have said that ambiguity is a problem for communication," says Ted Gibson, an MIT professor of cognitive science and senior author of a paper describing the research to appear in the journal Cognition. "But once we understand that context disambiguates, then ambiguity is not a problem it's something you can take advantage of, because you can reuse easy [words] in different contexts over and over again."

Lead author of the paper is Steven Piantadosi PhD '11; Harry Tily, a postdoc in the Department of Brain and Cognitive Sciences, is another co-author.

What do you 'mean'?

For a somewhat ironic example of ambiguity, consider the word "mean." It can mean, of course, to indicate or signify, but it can also refer to an intention or purpose ("I meant to go to the store"); something offensive or nasty; or the mathematical average of a set of numbers. Adding an 's' introduces even more potential definitions: an instrument or method ("a means to an end"), or financial resources ("to live within one's means").

But virtually no speaker of English gets confused when he or she hears the word "mean." That's because the different senses of the word occur in such different contexts as to allow listeners to infer its meaning nearly automatically.

Given the disambiguating power of context, the researchers hypothesized that languages might harness ambiguity to reuse words most likely, the easiest words for language processing systems. Building on observation and previous studies, they posited that words with fewer syllables, high frequency and the simplest pronunciations should have the most meanings.

To test this prediction, Piantadosi, Tily and Gibson carried out corpus studies of English, Dutch and German. (In linguistics, a corpus is a large body of samples of language as it is used naturally, which can be used to search for word frequencies or patterns.) By comparing certain properties of words to their numbers of meanings, the researchers confirmed their suspicion that shorter, more frequent words, as well as those that conform to the language's typical sound patterns, are most likely to be ambiguous trends that were statistically significant in all three languages.

To understand why ambiguity makes a language more efficient rather than less so, think about the competing desires of the speaker and the listener. The speaker is interested in conveying as much as possible with the fewest possible words, while the listener is aiming to get a complete and specific understanding of what the speaker is trying to say. But as the researchers write, it is "cognitively cheaper" to have the listener infer certain things from the context than to have the speaker spend time on longer and more complicated utterances. The result is a system that skews toward ambiguity, reusing the "easiest" words. Once context is considered, it's clear that "ambiguity is actually something you would want in the communication system," Piantadosi says.

Implications for computer science

The researchers say the statistical nature of their paper reflects a trend in the field of linguistics, which is coming to rely more heavily on information theory and quantitative methods.

"The influence of computer science in linguistics right now is very high," Gibson says, adding that natural language processing (NLP) is a major goal of those operating at the intersection of the two fields.

Piantadosi points out that ambiguity in natural language poses immense challenges for NLP developers. "Ambiguity is only good for us [as humans] because we have these really sophisticated cognitive mechanisms for disambiguating," he says. "It's really difficult to work out the details of what those are, or even some sort of approximation that you could get a computer to use."

But, as Gibson says, computer scientists have long been aware of this problem. The new study provides a better theoretical and evolutionary explanation of why ambiguity exists, but the same message holds: "Basically, if you have any human language in your input or output, you are stuck with needing context to disambiguate," he says.

Contact: Caroline McCall
Massachusetts Institute of Technology

Related medicine news :

1. Advantages and motivations uncertain behind use of brachytherapy for breast cancer radiotherapy
2. Tart cherry juice drinkers gain sleep advantage
3. Kids of Unhealthy, Disadvantaged Moms More Likely to Be Sickly
4. Complex choices in Medicare Advantage program may overwhelm seniors, study finds
5. Massachusetts health-care reform increased access to care, particularly among disadvantaged
6. Age, gender and social advantage affect success in quitting smoking
7. For back, neck pain, artificial disc replacement has cost, outcome advantages over fusion surgery
8. People Dropping Medicare Advantage Urged to Analyze Options
9. Colorectal cancer survival advantage in MUTYH-associated polyposis
10. New Polio Vaccine Shows Major Advantages: Study
11. Mission Critical Systems and Dress for Success Denver team up to train disadvantaged Colorado women
Post Your Comments:
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand gesture animations, FCPX users ... - CEO of Pixel Film Studios. , ProHand Cartoon’s package transforms over 1,300 ... Pro X . Simply select a ProHand generator and drag it above media or ...
(Date:6/25/2016)... ... 2016 , ... As a lifelong Southern Californian, Dr. Omkar Marathe earned his ... David Geffen School of Medicine at UCLA. He trained in Internal Medicine at Scripps ... in hematology/oncology at the UCLA-Olive View-Cedars Sinai program where he had the opportunity to ...
(Date:6/25/2016)... ... , ... On Friday, June 10, Van Mitchell, Secretary of the Maryland Department ... in recognition of their exemplary accomplishments in worksite health promotion. , The Wellness at ... Wellness Symposium at the BWI Marriott in Linthicum Heights. iHire was one of 42 ...
(Date:6/24/2016)... ... 2016 , ... A recent article published June 14 on E ... goes on to state that individuals are now more comfortable seeking to undergo not ... as calf and cheek reduction. The Los Angeles area medical group, Beverly Hills Physicians ...
(Date:6/24/2016)... ... 2016 , ... June 19, 2016 is World Sickle Cell Observance Day. In ... benefits of holistic treatments, Serenity Recovery Center of Marne, Michigan, has issued ... Sickle Cell Disease (SCD) is a disorder of the red blood cells, which can ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... 23, 2016 Research and Markets ... Market by Type (Organic Chemical (Sugar, Petrochemical, Glycerin), Inorganic ... Coating, Parenteral) - Global Forecast to 2021" report ... The global pharmaceutical excipients market is projected to ... of 6.1% in the forecast period 2016 to 2021. ...
(Date:6/23/2016)... Research and Markets has announced the ... report to their offering. ... favourable commercial environment for MedImmune to enter. The US ageing ... serve to drive considerable growth for effective anti-influenza medications. The ... sales considerably, but development is still in its infancy. ...
(Date:6/23/2016)... , June 23, 2016 Revolutionary ... Oticon , industry leaders in advanced audiology ... of Oticon Opn ™, the world,s first internet ... possibilities for IoT devices.      (Photo: ... introduces a number of ,world firsts,: , ...
Breaking Medicine Technology: