1. A computer-implemented method, comprising: receiving a first segment of text data, identifying data features corresponding to a sequence of characters in the first segment of text data, generating predictive annotations to the sequence of characters based at least in part on the identified data features, identifying inaccurate annotations generated according to the predictive annotations, correcting the identified inaccurate annotations, generating at least one set of model training data incorporating the corrected annotations, and monitoring progress of annotations made to a second segment of text data associated with the first segment of text data by a plurality of collaborating users of a plurality of managed computers, the monitoring including determining, based at least in part on a training descriptor corresponding to the second segment of text data, a state of completion of annotations made to the second segment of text data by a particular one of the plurality of collaborating users, wherein the training descriptor identifies types of annotations in the at least one set of model training data.