Context and motivation: Requirements as captured in user stories often must be split to facilitate further work. There are many different theoretical descriptions on how user story splitting should be conducted in agile software development. However, current research does not give insight into how teams and team members conduct user story splitting in practice. Question/problem: Our research aims to decrease the gap between the theory and the practice by exploring why, how, and what the impact is of user story splitting for the participants within the context. Principal ideas/results: Through interviews and observations, we see indications of purposes which the majority of the participants have in common. Their practices are similar to those found in the literature but not specifically prescribed from any specific source. As a result of their practices, many participants describe that they receive an understanding that they previously did not have. The participants are also able to deliver results incrementally and estimate their work with higher precision. Contribution: We use our results to provide guidelines on user story splitting and to guide further research on the topic.