1. A method for processing documents comprising: constructing, via a programmed processor device, a hidden feature space from one or more text document examples of a source domain, said one or more text document examples tagged with one or more labels of a source domain label space; and, simultaneously training one or more classifiers for use in classifying text documents, said classifiers trained on said one or more text document examples and said hidden feature space; receiving, at said processor device, one or more partially observed text document examples from a target domain; reconstructing, at said processor device, said partially observed text document examples of said target domain based on said constructed hidden feature space; and, predicting the labels of said partially observed text document examples based on the reconstructed target domain text document examples and said one or more trained classifiers.