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<p>effort.</p>

<p>In the statistical learning era, NER was usually performed by learning a simple linear regression model on <a href="page.php?w=Feature_engineering">engineered features</a>, then decoded by a bidirectional <a href="page.php?w=Viterbi_algorithm">Viterbi algorithm</a>. Some commonly used features include:</p>

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* Lexical items: The token itself be labeled.<br/>
* <a href="page.php?w=Stemming">Stemmed</a> lexical items.<br/>
* Shape: The <a href="page.php?w=Orthography">orthographic pattern</a> of the target word. For example,</p><p>
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