Abstract: Writing is a common task for crowdsourcing researchers exploring complex and creative work. To better understand how we write with crowds, we conducted both a literature review of crowd-writing systems and structured interviews with designers of such systems. We argue that the cognitive process theory of writing described by Flower and Hayes (1981), originally proposed as a theory of how solo writers write, offers a useful analytic lens for examining the design of crowd-writing systems. This lens enabled us to identify system design challenges that are inherent to the process of writing as well as design challenges that are introduced by crowdsourcing. The findings present both similarities and differences between how solo writers write versus how we write with crowds. To conclude, we discuss how the research community might apply and transcend the cognitive process model to identify opportunities for future research in crowd-writing systems.