4. Scoring and Incentivizing Workers
V. Raykar, S. Yu, L. Zhao, G. Valadez, C. Florin, L. Bogoni, and L. Moy. Learning
from crowds. Journal of Machine Learning Research, 99:1297–1322, 2010.
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7. Collecting Labels
• Partition examples into subsets
• For each example in the current partition
– Collect 2k labels for the example
– If Jaccard agreement & high confidence
• Declare aggregate label as “pseudo-gold”
– Else if within budget and trusted workers exist
• Collect another label and re-test for pseudo-gold
– Else
• Give up, output best guess aggregate label
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8. Identifying Trusted Workers
• For a subset of psuedo-gold examples
– Collect 2k labels for the example
• For each worker
– If spammer score > 0.5 over >= 100 examples
• Add worker to trusted pool
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12. Key Points
• Some interesting ideas to explore further
– Interface design
– Online label analysis (cf. Welinder & Perona’10)
– Personalized error reports for workers
• Some nice properties
– Unsupervised, 44K labels for $40, rapid development
• Preliminary results, more analysis needed…
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13. Thanks!
NIST: Ellen & Ian
Track Org: Gabriella & Mark
ir.ischool.utexas.edu/crowd
Support
– Temple Fellowship
Matt Lease - ml@ischool.utexas.edu - @mattlease