RT Journal Article SR Electronic T1 Crowdsourcing Image Analysis for Plant Phenomics to Generate Ground Truth Data for Machine Learning JF bioRxiv FD Cold Spring Harbor Laboratory SP 265918 DO 10.1101/265918 A1 Zachary D Siegel A1 Naihui Zhou A1 Scott Zarecor A1 Nigel Lee A1 Darwin A Campbell A1 Carson M Andorf A1 Dan Nettleton A1 Carolyn J Lawrence-Dill A1 Baskar Ganapathysubramanian A1 Iddo Friedberg A1 Jonathan W Kelly YR 2018 UL http://biorxiv.org/content/early/2018/02/14/265918.abstract AB The accuracy of machine learning tasks is critically dependent on high quality ground truth data. Therefore, in many cases, producing good ground truth data typically involves trained professionals; however, this can be costly in time, effort, and money. Here we explore the use of crowdsourcing to generate a large number of training data points of good quality. We explore an image analysis task involving the segmentation of corn tassels from images taken in a field setting. We explore the accuracy, speed and other quality metrics when this task is performed by students for academic credit, Amazon MTurk workers, and Master Amazon MTurk workers. We conclude that the Amazon MTurk and Master Mturk workers perform significantly better than the for-credit students, with no significant difference between the two MTurk worker types. The quality of the segmentation produced by Amazon MTurk workers rivals that of an expert worker. We provide best practices to assess the quality of ground truth data, and to compare data quality produced by different sources. We conclude that properly managed crowdsourcing can be used to establish large volumes of viable ground truth data at a low cost and high quality, especially in the context of high throughput plant phenotyping. We also provide several metrics for assessing the quality of the generated datasets.