This project is a prototype for experimental purposes only and production grade code is not released here.
Deep LSTM siamese network for text similarity
It is a tensorflow based implementation of deep siamese LSTM network to capture phrase/sentence similarity using character embeddings.
This code provides architecture for learning two kinds of tasks:
-
Phrase similarity using char level embeddings [1]
-
Sentence similarity using word level embeddings [2]
For both the tasks mentioned above it uses a multilayer siamese LSTM network and euclidian distance based contrastive loss to learn input pair similairty.
Capabilities
Given adequate training pairs, this model can learn Semantic as well as structural similarity. For eg:
Phrases :
- International Business Machines = I.B.M
- Synergy Telecom = SynTel
- Beam inc = Beam Incorporate
- Sir J J Smith = Johnson Smith
- Alex, Julia = J Alex
- James B. D. Joshi = James Joshi
- James Beaty, Jr. = Beaty
For phrases, the model learns character based embeddings to identify structural/syntactic similarities.
Sentences :
- He is smart = He is a wise man.
- Someone is travelling countryside = He is travelling to a village.
- She is cooking a dessert = Pudding is being cooked.
- Microsoft to acquire Linkedin β Linkedin to acquire microsoft
(More examples Ref: semEval dataset)
For Sentences, the model uses pre-trained word embeddings to identify semantic similarities.
Categories of pairs, it can learn as similar:
- Annotations
- Abbreviations
- Extra words
- Similar semantics
- Typos
- Compositions
- Summaries
Training Data
-
Phrases:
- A sample set of learning person name paraphrases have been attached to this repository. To generate full person name disambiguation data follow the steps mentioned at:
https://github.com/dhwajraj/dataset-person-name-disambiguation
"person_match.train" : https://drive.google.com/open?id=1HnMv7ulfh8yuq9yIrt_IComGEpDrNyo-
-
Sentences:
- A sample set of learning sentence semantic similarity can be downloaded from:
"train_snli.txt" : https://drive.google.com/open?id=1itu7IreU_SyUSdmTWydniGxW-JEGTjrv
This data is generated using SNLI project :
- word embeddings: any set of pre-trained word embeddings can be utilized in this project. For our testing we had used fastText simple english embeddings from https://github.com/facebookresearch/fastText/blob/master/pretrained-vectors.md
alternate download location for "wiki.simple.vec" is : https://drive.google.com/open?id=1u79f3d2PkmePzyKgubkbxOjeaZCJgCrt
Environment
- numpy 1.11.0
- tensorflow 1.2.1
- gensim 1.0.1
- nltk 3.2.2
How to run
Training
$ python train.py [options/defaults]
options:
-h, --help show this help message and exit
--is_char_based IS_CHAR_BASED
is character based syntactic similarity to be used for phrases.
if false then word embedding based semantic similarity is used.
(default: True)
--word2vec_model WORD2VEC_MODEL
this flag will be used only if IS_CHAR_BASED is False
word2vec pre-trained embeddings file (default: wiki.simple.vec)
--word2vec_format WORD2VEC_FORMAT
this flag will be used only if IS_CHAR_BASED is False
word2vec pre-trained embeddings file format (bin/text/textgz)(default: text)
--embedding_dim EMBEDDING_DIM
Dimensionality of character embedding (default: 100)
--dropout_keep_prob DROPOUT_KEEP_PROB
Dropout keep probability (default: 0.5)
--l2_reg_lambda L2_REG_LAMBDA
L2 regularizaion lambda (default: 0.0)
--max_document_words MAX_DOCUMENT_WORDS
Max length (left to right max words to consider) in
every doc, else pad 0 (default: 100)
--training_files TRAINING_FILES
Comma-separated list of training files (each file is
tab separated format) (default: None)
--hidden_units HIDDEN_UNITS
Number of hidden units(default:50)
--batch_size BATCH_SIZE
Batch Size (default: 128)
--num_epochs NUM_EPOCHS
Number of training epochs (default: 200)
--evaluate_every EVALUATE_EVERY
Evaluate model on dev set after this many steps
(default: 2000)
--checkpoint_every CHECKPOINT_EVERY
Save model after this many steps (default: 2000)
--allow_soft_placement [ALLOW_SOFT_PLACEMENT]
Allow device soft device placement
--noallow_soft_placement
--log_device_placement [LOG_DEVICE_PLACEMENT]
Log placement of ops on devices
--nolog_device_placement
Evaluation
$ python eval.py --model graph#.pb
Performance
Phrases:
- Training time: (8 core cpu) = 1 complete epoch : 6min 48secs (training requires atleast 30 epochs)
- Contrastive Loss : 0.0248
- Evaluation performance : similarity measure for 100,000 pairs (8core cpu) = 1min 40secs
- Accuracy 91%
Sentences:
- Training time: (8 core cpu) = 1 complete epoch : 8min 10secs (training requires atleast 50 epochs)
- Contrastive Loss : 0.0477
- Evaluation performance : similarity measure for 100,000 pairs (8core cpu) = 2min 10secs
- Accuracy 81%