title: What does representation matrix of context word mean in SkipGram?
body: <p>I am learning Stanford NLP Course and I have issue understanding a concept in Skipgram from picture below.</p>
  
  <p><a href="https://i.stack.imgur.com/0XwOX.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0XwOX.jpg" alt="enter image description here"></a>
  From left to right, the first column vector is one-hot encoder, the second is the word embedding matrix from 1-layer neural network, the third is word representation vector. However, when it comes to the fourth one, which is a matrix with 'v by d' dimension. Not sure if I listen it correctly, but the speaker said this is a representation of context word and these three matrix are identical? </p>
  
  <p>My questions are:
  1. Why these three matrix are identical but the three multiplication results are different?
  2. How do we get this matrix (v by d dimension)?</p>
  
  <p>The link to the lecture is: </p>
  
  <p><a href="https://www.youtube.com/watch?v=ERibwqs9p38&amp;t=1481s" rel="nofollow noreferrer">https://www.youtube.com/watch?v=ERibwqs9p38&amp;t=1481s</a></p>