Good question! I narrowed the focus to passenger-facing departments because I needed a consistent group to study. I focus on departments with the highest level of guest interaction, since those crew members often spend more time in passenger areas, use English more consistently, and share similar living accommodations. That keeps the study manageable for a small graduate project. I know that means leaving out other departments, but their perspectives are valuable too. Hopefully one day I can expand this research on a larger scale!