title: How to initialize word-embeddings for Out of Vocabulary Word?
body: <p>I am trying to use CoNLL-2003 NER (English) Dataset and I am trying to utilize pretrained embeddings for it. I am using SENNA pretrained embeddings. Now I have around 20k words in my vocabulary and out of this I have embedding available for only 9.5k words.<br>
  My current approach is to initialize an array of <code>20k X embedding_size</code> with zeros and initialize the 9.5k words whose embeddings is known to me and make all the embeddings learn-able.<br></p>
  
  <p>My question is what is the best way to do this? Any reference to such research will be very helpful?</p>