I was asked to be a statistician in a research (survey). The respondents were hospital personnel from our local hospital with a population size of 173. Respondents were asked (via questionnaire) what they think about the implementation of healthcare waste management practices in the hospital, and they may choose Fully Implemented, Partially Implemented or Not Implemented for each question. The researcher distributed the questionnaires to the whole population but she's being advised by her teacher to just use a sample size for the research. Now I do know of Slovin's formula which is widely used in our country but is now being questioned.
This is the formula
n = N/(1+Ne^2) where: n = sample size N = pop size e = margin of error
I don't think i will be using it if it is being questioned. What method would you use to determine the sample size in this case?