  Recently datasets that contain sentence descriptions of images have enabled
models that can automatically generate image captions. However, collecting
these datasets are still very expensive. Here, we present SentenceRacer, an
online game that gathers and verifies descriptions of images at no cost.
Similar to the game hangman, players compete to uncover words in a sentence
that ultimately describes an image. SentenceRacer both generates and verifies
that the sentences are accurate descriptions. We show that SentenceRacer
generates annotations of higher quality than those generated on Amazon
Mechanical Turk (AMT).
