Changes between Version 15 and Version 16 of i2b2 AUG 2013


Ignore:
Timestamp:
06/24/13 12:30:57 (11 years ago)
Author:
Richard Bramley
Comment:

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  • i2b2 AUG 2013

    v15 v16  
    147147
    148148=== [=#NLP6 Active Learning for Ontology-based Phenotyping] ===
     149
     150Presentation on a proposed Active Learning method to reduce the number of training examples an algorithm requires for machine learning, as annotation of examples is slow and expensive.
     151
     152The normal method for training an NLP algorithm is to randomly select a potion of the data to annotate.  This method proposes initially annotating a small number of random samples and selecting subsequent samples to annotate based on the algorithm's output for that sample having a low ''prediction margin''.
     153
     154'''Prediction Margin = confidence for class A - confidence for class B'''
     155
     156In other words, how sure it is that the best answer is correct.
     157
     158The presentation showed that in general (but not for every example) the Active Learning method needed fewer annotated examples to reach a high level of confidence.
     159
    149160=== [=#NLP7 Conclusion] ===
     161
     162These are the conclusions that I (Richard Bramley) drew from the NLP conference.
     163
     1641. There are a lot of tools and resources available.  The integration of the cTakes tools with UMLS seems especially useful.
     1651. Access to clinician time to train NLP algorithms is '''essential'''.
     1661. The statistical analysis of the results is beyond my current capabilities.  I may need some training in this area.
    150167
    151168== Academic User Group ==