9. A system comprising: one or more data processing apparatus; and a computer-readable storage device having stored thereon instructions that, when executed by the one or more data processing apparatus, cause the one or more data processing apparatus to perform operations comprising: calculating one or more types of suggestion scores for each of a plurality of training examples wherein each type of suggestion score is based at least in part on a plurality of computed predictions for each training example generated by a plurality of different trained models, including weighting each type of suggestion score by an accuracy of the trained model that generated the prediction; calculating an overall suggestion score for each training example based at least in part on a combination of the one or more types of suggestion scores for each training example; ranking the training examples by the corresponding overall suggestion scores; and providing one or more highest-ranked training examples as a set of suggested training examples.
9. A system comprising: one or more data processing apparatus; and a computer-readable storage device having stored thereon instructions that, when executed by the one or more data processing apparatus, cause the one or more data processing apparatus to perform operations comprising: calculating one or more types of suggestion scores for each of a plurality of training examples wherein each type of suggestion score is based at least in part on a plurality of computed predictions for each training example generated by a plurality of different trained models, including weighting each type of suggestion score by an accuracy of the trained model that generated the prediction; calculating an overall suggestion score for each training example based at least in part on a combination of the one or more types of suggestion scores for each training example; ranking the training examples by the corresponding overall suggestion scores; and providing one or more highest-ranked training examples as a set of suggested training examples. 16. The system of claim 9 , wherein the operations further comprise: requesting one or more additional training examples based on one or more of the highest-ranked training examples; receiving one or more additional training examples in response to the request; updating each trained model using the one or more received additional training examples; and recalculating suggestion scores for each of the plurality of training examples and the one or more received additional training examples; and providing one or more highest-ranked training examples based on the recalculated suggestion scores.