1. 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 first set of elements from a group of elements for labeling by one or more human users; receiving a label of each element of the first set of elements from the one or more human users; determining a sample selection bias of the first set of elements; training a model for predicting labels based at least in part on the received labels of the selected first set of elements, and the sample selection bias of the first set of elements; determining a sample selection bias of a second set of elements; selecting the second set of elements from a group of elements for labeling by one or more human users, the selecting based at least in part on the sample selection bias of the second set of elements; receiving a label of each element of the second set of elements from the one or more human users; training a model for predicting labels based at least in part on the labels of each element of the second set of elements, and the sample selection bias of the second set of elements; and repeating the determining of the sample selection bias, the selecting of a set of elements, the receiving, and the training until a trained model satisfies a stop condition, wherein the stop condition comprises a predefined number of elements being labeled by the one or more human users or an error threshold is reached.