"I Hope This Is Helpful": Understanding Crowdworkers' Challenges and Motivations for an Image Description Task

AI image captioning challenges encourage broad participation in designing algorithms that automatically create captions for a variety of images and users. To create large datasets necessary for these challenges, researchers typically employ a shared crowdsourcing task design for image captioning. This paper discusses findings from our thematic analysis of 1,064 comments left by Amazon Mechanical Turk workers using this task design to create captions for images taken by people who are blind. Workers discussed difficulties in understanding how to complete this task, provided suggestions of how to improve the task, gave explanations or clarifications about their work, and described why they found this particular task rewarding or interesting. Our analysis provides insights both into this particular genre of task as well as broader considerations for how to employ crowdsourcing to generate large datasets for developing AI algorithms.