Techniques are described for facilitating interactions between task requesters who have tasks available to be performed and task performer users who are available to perform tasks, such as interactions that enable improvement of unsatisfactory task performance results from human task performer users. In some situations, after a task performer user has generated initial results from performance of a task supplied by a task requester, the task requester indicates that the initial results are only partially satisfactory (e.g., only partially satisfy one or more criteria for the task performance results), and may result in only a partial payment rather than a full payment amount associated with fully satisfactory performance of the task. The task requester may also supply information to provide one or more opportunities to the task performer user to supply additional improved supplemental results (e.g., so as to receive the full payment amount).