The aim of the current study is to present the methodology for exploring code choice in the context of Tunisian higher education focusing on the use of Code Switching (CS). The study addresses these two research questions: To what extent and in what circumstances are Arabic, French and English used in Tunisian higher education contexts? What are the functions of code choice and code switching? To find answers to the research questions, this study leans on two types of observations namely informal observation and formal observation. The informal observation took place in informal settings, namely university corridors, libraries and eateries and the formal observation was conducted in classrooms. The aim of the informal observation is to investigate the languages used by students in public places. The classroom observation is used again to investigate the languages used in classes. After presenting the observation charts, the researchers presented the procedure of piloting. Due to the COVID situation, the researchers suggested piloting the observation charts by the use of recorded videos from Tunisian students’ university life, videos on multilingual classrooms and online courses. The study may methodologically contribute to the literature of observation design and validation.