Like Word2vec is not a single algorithm but combination of two, namely, CBOW and Skip-Gram model; is Doc2Vec also a combination of any such algorithms? Or is it an algorithm in itself?
Word2Vec is not a combination of two models, rather both are variants of word2vec. Similarly doc2vec has Distributed Memory(DM) model and Distributed Bag of words (DBOW) model. Based on the context words and the target word, these variants arised.
Note: the name of the model maybe confusing
Distriubted Bag of wordsis similar to
Distributed Memoryis similar to
Continuous bag of words model
Deep learning via the distributed memory and distributed bag of words models from , using either hierarchical softmax or negative sampling , .
1$\begingroup$ Those are algorithms used for approximation. and you could use hierarchical softmax or negative sampling in any models, CBOW or SG. $\endgroup$– chmodsssJul 10, 2017 at 11:43
$\begingroup$ Are DM and DBOW deep learning? I have read CBOW and SG uses a shallow neural network to predict word/context. Shouldn't it be the same for Doc2Vec? $\endgroup$– KshitizJul 10, 2017 at 19:28
doc2vecuses the same algorithm as
word2vec, except that it uses sentence labels. None of the models are deep learning to be specific. As deep learning model should have multiple hidden layers. Since, deep learning is mostly involved with big data and
doc2vecmostly works with big data, some term it as deep learning model. But actually it is not. $\endgroup$– chmodsssJul 11, 2017 at 7:29
Distributed Memory model preserves the word order in a document whereas Distributed Bag of words just uses the bag of words approach, which doesn't preserve any word order.
This has been explained in details in this research paper.
$\begingroup$ No problem, and welcome to Data Science! $\endgroup$– Stephen Rauch ♦Mar 21, 2018 at 4:24