Useful reference: Properties of Sparse Distributed Representations

- What are disadvantages of SDR’s?
- What does the “distributed” part of SDR mean?
- Why is sparsity necessary? How sparse do representations need to be? Can they be too sparse?
- Which is better? n=1000 and w=3 or n=300 and w=15
- For representations with 33 active bits out of 500 total, how many unique representations are there? If we randomly generate 100 of these representations, how likely is it that two of the hundred will be identical? If we randomly generate two of these representations, how likely is it that they will share more than 5 active bits?
- When creating an encoder for a new data type, what makes a good SDR? How can you test that the SDRs that are produced are good?
- How would you encode sound as SDRs?