temporal expressions in bio medical texts

8/2/2019 Temporal Expressions in Bio Medical Texts

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Michele Filannino

COMP80122: final presentation

Manchester, 29/02/2012

temporal expressionsidentification in biomedical texts


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/ 2329/02/2012, Michele Filannino

presentation temporal expressions

where we are

Computer science natural language processing

information extraction

temporal expressions extraction

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1 L. Ferro, I. Mani, B. Sundheim, and G. Wilson, Tides temporal annotationguidelines, v. 1.0.2, MITRE, 2001

tem oral ex ression definition

natural language phrase that denotes a temporalentity: an interval, or an instant (Ferro et Al.)1

She has been at work for more than a month

He wrapped up a three-hour meeting with the Iraqi

president in Baghdad today.

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wh ?

users perspective

temporal aspects of events and entities provide anatural mechanism for organising information.

machines perspective

improvements in

question answering, summarisation, browsing

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wh clinical domain?

diagnosis explanation

disease progression

modelling

analysis of effectiveness of

treatment

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Source: Google Scholar (last update 27/02/2012)

scientific interest

6

0

7

14

21

28

35

42

49

56

63

70

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

temporal expressions AND clinical


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1 J. Poveda, M. Surdeanu, and J. Turmo, An analysis of Bootstrapping for theRecognition of Temporal Expressions, 2009

tem oral forms1

time or date references

11pm, February 14th, 2005

time references that anchor on another time one hour after midnight, two weeks before Christmas

durations

few months, two days, five years recurring times

every third month, twice in the hour

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1 J. Poveda, M. Surdeanu, and J. Turmo, An analysis of Bootstrapping for theRecognition of Temporal Expressions, 2009

tem oral forms1

context-dependent times

today, last year

vague references somewhere in the middle of June, the near future

times indicated by an event

the day S. Berlusconi resigned an event is considered a cover term for situations that

happen or occur

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methodolo

annotation

recognition

automatically detect and delimitate expressions

mostly machine-learning techniques

normalisation

assign attributes values for all the recognised

expressions

using a shared and formal format

mostly rule-based techniques

reasoning or searching

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Source: TRIOS TimeBank v.0.1

exam le: raw text

That means Unisys must pay about $100 million in interest every

quarter, on top of $27 million in dividends on preferred stock.

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exam le: reco nition

That means Unisys must pay about $100 million in

interest every quarter, on top of $27 million in

dividends on preferred stock.

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exam le: normalisation

That means Unisys must pay

about $100 million in interest every quarter, on top of $27 million in dividends on preferred stock.

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lack of cor ora

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m contributions

built the first timex corpus using all the possible

freely available timexes

{timex, type, normalised_value, utterance_reference}

2822 different timexes

built a normaliser

as TRIOS extension (University of Rochester)

71.66% accuracy from 62.57%

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human mistakes

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utterance expression type annotation

- three years before DATE FUTURE_REF

26/09/2011 this morning DATE 1998-02-06TMO

- two decades DURATION P20Y

- the summer of 1862 DATE FUTURE_REF

- centuries DURATION PXE

- the last half of 80s DATE 198


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Thankyou.

temporal expressions in bio medical texts

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