Hasan is most likely conducting a qualitative research study. Qualitative research involves gathering detailed data through interviews, observations, or other methods, and then analyzing that data to understand the underlying meanings, patterns, and perspectives. In Hasan's case, he's interviewing a child with ADHD and studying the data in detail to gain insights into the child's experiences, behaviors, and challenges. This approach allows researchers like Hasan to explore complex phenomena in depth and understand them from the perspective of the participants.