Abstract
Workflow-based science gateways that bring the power of scientific workflows to the Web are becoming increasingly popular. Different IO models enabling interactions between a running workflow and web portal have been explored. However, these are typically not dynamic enough to allow users to insert data into, or export data out of, a continuously running workflow. In this paper, we present a novel IO model, which supports dynamic interaction between a workflow and its portal. We discuss a use case in which web portal are used to control the execution of scientific workflows. This IO model will be part of our workflow-based science gateway named WorkWays.