Presentation in ARTEL workshop on ECTEL 2015 Reflection and collaborative reflection are common ac-tivities at workplace, in which people alone or together with col-leagues revisit experiences to learn for future situations. Often sup-port needs arise during reflection and for example people get stuck and don’t know how to continue. We propose to fill this gap with prompting as tool-supported scaffolding mechanism. Based on liter-ature and our own previous work on reflections support this paper presents a concept using prompting to support different goals based on known support needs in tool-supported collaborative reflection. We show an initial implementation of a prototype and an approach how to evaluate it. This work contributes to the (AR)TEL commu-nity in that it provides a concrete approach for scaffolding in reflec-tion support to be discussed at the workshop and in that it shows how prompting can be used and implemented in tools to evoke re-flection.