論文アブストラクト：The increasing popularity of mobile crowdsourcing platforms has enabled crowd workers to accept jobs wherever/whenever they are, and also provides opportunity for task requesters to order time/location specific tasks to workers. Since workers on mobile platforms are working on the go, the situation of the workers is expected to influence their performance. However, the effects of mobile worker situations to task performance is an uninvestigated area. In this paper, our research question is, "do worker situations affect task completion, price and quality on mobile crowdsourcing platforms?" We draw on economics and psychology research to examine whether worker situations such as busyness, fatigue and presence of companions affect their performance. Our three-week between-subjects field experiment revealed that worker busyness caused 30.1% relative decrease of task completion rate. Mean accepted task price increased by 7.6% when workers are with companions. Worker fatigue caused 37.4% relative decrease of task quality.