Ratinov and Roth ( 2009 ) present detailed studies on the task of named entity recognition , which discusses and compares different methods on multiple aspects including chunk representation , inference method , utility of non-local features , and integration of external knowledge .
design challenges and misconceptions in named entity recognition
L Ratinov D Roth
However , the phrases detected are not necessarily mentions that we need to discover . Ratinov and Roth ( 2009 ) present detailed studies on the task of named entity recognition , which discusses and compares different methods on multiple aspects including chunk representation , inference method , utility of non-local features , and integration of external knowledge . NER can be regarded as a sequential labeling problem , which can be modeled by several proposed models , e.g. Hidden Markov Model ( Rabiner , 1989 ) or Conditional Random Fields ( Sarawagi and Cohen , 2004 ) .
@@CITATION present detailed studies on the task of named entity recognition , which discusses and compares different methods on multiple aspects including chunk representation , inference method , utility of non-local features , and integration of external knowledge .