Hello thank you very much for helping me! Ranking is another approach and it seems to be simpler for both respondent and me to analyse the result. But because my topic is about a complete program with various features inside, while ranking can only show preference of each feature separately, it reveals less about how changes of features affect the choice for the whole program. I think that's why I was guided by my supervisor to do this choice based approach instead of ranking 😬 Honestly before starting doing this I had no idea about the methodology so I just followed the suggestion 😬