The document discusses three main challenges of crowdsourcing data: 1) crowdsourcing data, 2) human motivation, and 3) behavioral design. It explores theories of human motivation and how interface design can affect behavior. Specific examples are discussed, such as default choice bias and how interface elements in applications like Snackbot can influence user choices. The document advocates for social interfaces to draw from social and cognitive science regarding crowd data analysis, motivation, and designs that compel human participation and empowerment.