13. A system of searching for semantically equivalent questions using hybrid representations in a computer-implemented community of question and answer system, comprising: one or more hardware processors operable to receive a first question in natural language via a user interface over a communication network, one or more of the hardware processors further operable to parse the first question into tokens using a natural language processing technique, one or more hardware processors further operable to generate in-memory weighted bag of words representation of the first question based on the tokens, wherein weights associated with the bag of words are determined by training a neural network to learn the weights, one or more hardware processors further operable to generate in-memory convolutional neural networks based distributed vector representation of the first question based on the tokens, wherein parameters of the convolutional neural networks based distributed vector representation are determined by training the neural network to learn the parameters, one or more hardware processors further operable to retrieve a second question from a pool of questions stored in a storage device, wherein the second question is represented in in-memory weighted bag of words representation and in-memory convolutional neural networks based distributed vector representation, one or more hardware processors further operable to determine semantic similarity between the first question and the second question as a function of a first similarity computed based on the in-memory weighted bag of words representations of the first question and the second question, and a second similarity computed based on the in-memory convolutional neural networks based distributed vector representations of the first question and the second question, wherein function parameters attributed to the first similarity and the second similarity in the function are learned by the neural network, wherein hardware memory representation of the neural network is transformed as the parameters are learned and updated.
13. A system of searching for semantically equivalent questions using hybrid representations in a computer-implemented community of question and answer system, comprising: one or more hardware processors operable to receive a first question in natural language via a user interface over a communication network, one or more of the hardware processors further operable to parse the first question into tokens using a natural language processing technique, one or more hardware processors further operable to generate in-memory weighted bag of words representation of the first question based on the tokens, wherein weights associated with the bag of words are determined by training a neural network to learn the weights, one or more hardware processors further operable to generate in-memory convolutional neural networks based distributed vector representation of the first question based on the tokens, wherein parameters of the convolutional neural networks based distributed vector representation are determined by training the neural network to learn the parameters, one or more hardware processors further operable to retrieve a second question from a pool of questions stored in a storage device, wherein the second question is represented in in-memory weighted bag of words representation and in-memory convolutional neural networks based distributed vector representation, one or more hardware processors further operable to determine semantic similarity between the first question and the second question as a function of a first similarity computed based on the in-memory weighted bag of words representations of the first question and the second question, and a second similarity computed based on the in-memory convolutional neural networks based distributed vector representations of the first question and the second question, wherein function parameters attributed to the first similarity and the second similarity in the function are learned by the neural network, wherein hardware memory representation of the neural network is transformed as the parameters are learned and updated. 16. The system of claim 13 , wherein the user interface comprises a browser associated with a search engine web site.