Existing research has established mobilizing frames as a driver of institutional change. However, we know little about how mobilizing frames emerge. This doctoral dissertation investigates how and when conversations can produce new mobilizing frames, i.e. action-oriented sets of beliefs and meanings. The empirical analysis of this dissertation is based on a longitudinal study of idea development conversations in a creative project between professionals from nine public health care organizations in Finland, 2009 - 2012. The three essays of this dissertation interpret the same empirical data through distinct theoretical 'lenses' developed in the essays. This research approach is called 'theoretical triangulation' and it is used to provide an in-depth understanding of the micro-to-macro conversational processes linking individual actors' discourse to the generation of mobilizing frames. The first essay takes an ecological perspective to investigate what characteristics of conversations are associated with the generation of influential ideas. The second essay develops a novel structuration perspective to study how conversations construct cultural structures, and how such cultural structures condition the subsequent negotiations concerning tangible changes in the organizations. The third essay studies how conversations construct conversational 'networks', and how such networks condition the selection of ideas as mobilizing frames. The findings suggest conversations are more likely to generate influential ideas when actors utilize a broad spectrum of genres, when actors shift between the genres frequently, when the population of conversed ideas is large, and when the average conversational attention per idea is low. In such temporally evolving and culturally diverse conversations, the development of nascent ideas into mobilizing frames is crucially dependent on the formation of inclusive, supportive, dense, and relatively stable conversational 'networks' where the idea advocate is centrally positioned. The findings are synthesized into a model describing the ecological relationship between the population of ideas and the conversational, cultural, and relational environment in which the ideas live and die. This novel perspective provides a theoretical answer to the important practical question of why change in the field of public health care is so slow.