Plenary 4 concentrates on quality, evaluation and research of ACP. Starting with Judith Rietjens, who is presenting a white paper defining optimal ACP, followed by Jürgen in der Schmitten, who approaches an operational definition of ACP. Linda Briggs talks about Case of ACP Facilitator Standards; Bud Hammes answers the question, what maintenance does an ACP Programme Need in order to be of continual high quality and Rebecca Sudore tells how to measure successful ACP.