[dan-robertson]

The number reuse is just the author being a bit lazy. You could estimate how similar these vectors are by seeing if they point in similar directions or by calculating the angle between them. Here they are about 60° apart and somewhat the same direction, but a lot of this is that the author didn’t want to put in any negative numbers in the example so vectors end up being a bit more similar than they would be really.

That the numbers are reused isn’t meaningful here: a 1 in the first position is quite unrelated to a 1 in the second (as no convolutions are done over this vector)

[dogline]

Thank you. I guess I need to back up. This is a vector, not just an identifier, and direction and angle seem important. I need to look up how the encoding is normally done, since this isn't obvious if you haven't worked in this domain before.

[kevindamm]

The encoding is typically learned, and if possible is part of the ANN so that it can be adjusted along with the other parameters.

A good place to start on that topic is the word2vec paper.