The present invention consists of a computer-implemented system and method for automatically analyzing and coding documents into content categories suitable for high cost, high yield settings where quality and efficiency of classification are essential. A prototypical example application field is legal document predictive coding for purposes of e-discovery and litigation (or litigation readiness) where the automated classification of documents as “responsive” or not must be (a) efficient, (b) accurate, and (c) defensible in court. Many text classification technologies exist but they focus on the relatively simple steps of using a training method on training data, producing a model and testing it on test data. They invariably do not address effectively and simultaneously key quality assurance requirements. The invention applies several data design and validation steps that ensure quality and removal of all possible sources of document classification error or deficiencies. The invention employs multiple classification methods, preprocessing methods, visualization and organization of results, and explanation of models which further enhance predictive quality, but also ease of use of models and user acceptance. The invention can be applied to practically any field where text classification is desired.