The present thesis studies the concept of collaborative creativity in the Writers' Room setting. It applies membership categorization analysis to explore the conversations during which co-screenwriters contribute to the creative process of screenwriting. The study is based on participatory observation of the 2024 Writers' Room program as part of the Serial Storytelling master's program at Internationale Filmschule Köln.

By considering the creative process as the two-step process of blind variation and selective retention - based on Donald Campbell (1960) - and socio-culturally contextualizing it - based on Mihaly Csikszentmihalyi (1998) - different membership categories that could be played within a screenwriting team had been identified. Then, the researcher experimented with those through his participatory observation in the Writers' Room and came up with an explanation. The mechanism of interaction between them was also depicted in a systems model.

The findings explain that co-screenwriters collaborate in the Writers' Room by playing dynamic membership roles during conversations. These roles can be categorized into (1) the Generator, (2) the Analyst, and (3) the Strategist. The role of each co-screenwriter can vary at each turn of their speech, and different parts of a turn of speech can fulfill different roles. The Generator role emerges when they blindly generate a new idea, the Analyst role manifests when they rationally discuss whether an idea works, and the Strategist role appears when they attempt to navigate the discussion.