This is an implementation of unsupervised smoothed inverse frequency (uSIF), a simple but effective way to create sentence embeddings without any labelled data (Best Paper, Repl4NLP @ ACL 2018). See the paper for more details.

*01/11/18 Code now works for Python3 instead of Python2.

1. Unzip the pre-trained ParaNMT word vectors (thanks to John Wieting for providing this).
2. Install the python packages in requirements.txt.
3. Initialize a uSIF embedding model with usif.py. Call get_paranmt_usif to get the model that uses the ParaNMT vectors and call test_STS to see if you get the expected results. Once you know it's working, feel free to try it with other word vectors.

If you don't have a sizable list of related sentences to embed, then there is not much point to doing piecewise common component removal, in which case you can set m = 0 when initializing uSIF. Even for STS tasks, setting m = 0 only decreases performance by 1 - 4%.

If you use this code, please cite

@article{ethayarajh2018unsupervised,
  title={Unsupervised Random Walk Sentence Embeddings: A Strong but Simple Baseline},
  author={Ethayarajh, Kawin},
  journal={ACL 2018},
  pages={91},
  year={2018}
}