17. A method for distributed data annotation, comprising: receiving source data using a distributed data annotation server system, where the source data comprises one or more pieces of source data; selecting one or more annotators for at least one piece of source data using the distributed data annotation server system; creating one or more annotation tasks for the selected annotators and at least one piece of source data using the distributed data annotation server system; requesting one or more annotations for at least one piece of source data using the created annotation tasks and the distributed data annotation server system; receiving annotations for at least one piece of source data using the distributed data annotation server system; determining source data metadata for at least one piece of source data using the received annotations and the distributed data annotation server system, where the source data metadata includes source data characteristics; generating annotator metadata for at least one annotator using the received annotations, at least one piece of source data, and the distributed data annotation server system, where the annotator metadata includes identified annotator characteristics; and estimating the ground truth for at least one piece of source data using the source data metadata, the annotator metadata, and the distributed data annotation server system.
17. A method for distributed data annotation, comprising: receiving source data using a distributed data annotation server system, where the source data comprises one or more pieces of source data; selecting one or more annotators for at least one piece of source data using the distributed data annotation server system; creating one or more annotation tasks for the selected annotators and at least one piece of source data using the distributed data annotation server system; requesting one or more annotations for at least one piece of source data using the created annotation tasks and the distributed data annotation server system; receiving annotations for at least one piece of source data using the distributed data annotation server system; determining source data metadata for at least one piece of source data using the received annotations and the distributed data annotation server system, where the source data metadata includes source data characteristics; generating annotator metadata for at least one annotator using the received annotations, at least one piece of source data, and the distributed data annotation server system, where the annotator metadata includes identified annotator characteristics; and estimating the ground truth for at least one piece of source data using the source data metadata, the annotator metadata, and the distributed data annotation server system. 28. The method of claim 17 , further comprising determining a cost for performing the annotation task using the distributed data annotation server system.