<p>You may be interested in this paper (accepted to EMNLP 2019): <a href="https://arxiv.org/abs/1903.11222" rel="nofollow noreferrer">https://arxiv.org/abs/1903.11222</a></p>

<p>In this paper, we experiment with several different ways of dealing with this exact problem (including the 2 mentioned by @christopher-manning above). TLDR, the main takeaways are:</p>

<ol>
<li>Using a truecaser on test data is a bad idea, because truecasers perform more poorly than you think.</li>
<li>Caseless models work pretty well.</li>
<li>But overall the best option is to augment the original training data with caseless training data (just <code>train_data.lower()</code>) and retrain the model. </li>
</ol>
How to recognize a named entity that is lowcase such as kobe bryant by CoreNLP?
<p>I got a problem that CoreNLP can only recognize named entity such as Kobe Bryant that is beginning with a uppercase char, but can't recognize kobe bryant as a person!!! So how to recognize a named entity that is beginning with a lowercase char by CoreNLP ???? Appreciate it !!!!</p>