Document classification using convolutional neural networks with small window sizes and latent semantic analysis

Abstract

A parsimonious convolutional neural network (CNN) for text document classification that replicates the ease of use and high classification performance of linear methods is presented. This new CNN architecture can leverage locally trained latent semantic analysis (LSA) word vectors. The architecture is based on parallel 1D convolutional layers with small window sizes, ranging from 1 to 5 words. To test the efficacy of the new CNN architecture, three balanced text datasets that are known to perform exceedingly well with linear classifiers were evaluated. Also, three additional imbalanced datasets were evaluated to gauge the robustness of the LSA vectors and small window sizes. The new CNN architecture consisting of 1 to 4-grams, coupled with LSA word vectors, exceeded the accuracy of all linear classifiers on balanced datasets with an average improvement of 0.73%. In four out of the total six datasets, the LSA word vectors provided a maximum classification performance on par with or better than word2vec vectors in CNNs. Furthermore, in four out of the six datasets, the new CNN architecture provided the highest classification performance. Thus, the new CNN architecture and LSA word vectors could be used as a baseline method for text classification tasks.