I have to analyze the results of a survey. The questions regard different motivators that the interviewees encounter ("I do it to help my colleagues" as a motivator for instance); all the answers are ordinal (1=strongly disagree -> 5=strongly agree) and the aim of this study is to see which factor (or set of factors) (nationality, age, site they work in, gender, role in the organization, center they belong) is influencing the answer.
I have looked in a lot of websites and lectures (ordered logit/probit model, discrete dependent variables, Likert scale, correlation, regressions, and so on) but it seems that my study could match a lot of ways to analyze these data.
So far I only have 15 interview results, which is not a lot: we expect around 100 answers at the end. I would like to have causal inference: their current behavior (motivations) should help us to draw a conclusion (causal effect, does their nationality influence their motivation factors?) regarding the factors of motivations. Could someone tell me which is the best way to treat these results?