17. One or more computer-readable media as recited in claim 13 , wherein the set of elements comprises a first set of elements, and further storing computer-executable instructions that, when executed on the one or more processors, cause the one or more processors to perform acts comprising: determining if the trained model satisfies a predefined stop condition; if the trained model satisfies the predefined stop condition, using the trained model to predict a label for multiple elements of the group of elements; otherwise: selecting a second set of elements from the group of elements for labeling by the one or more human users, the selecting based at least in part on a sample selection bias of the second set of elements; receiving a label for each element of the second set of elements from the one or more human users; and training a model for predicting labels for each element of the group of elements, the training based at least in part on the labels for the second set of elements received from the one or more human users and on the sample selection bias of the second set of elements.
13. One or more computer-readable media storing computer-executable instructions that, when executed on one or more processors, cause the one or more processors to perform acts comprising: selecting a set of elements having a sample selection bias from a group of elements for labeling by one or more human users, the selecting based at least in part on a sample selection bias of the set of elements; receiving a label for each element of the set of elements from the one or more human users; and training a model for predicting labels for each element of the group of elements, the training based at least in part on the labels for the set of elements received from the one or more human users.