You will find that you will need to read all the comments through and to categorise them after you have received them, or merely report them in their diversity and make general statements, or pick out particular comments if they seem to fit your purpose.
If you decide to use interviews: Questionnaires often seem a logical and easy option as a way of collecting information from people.
Look at the very brief outlines of different methods below.
Consider which you intend using and whether you could also find it more useful to combine the quantitative with the qualitative.
Your research will dictate the kinds of research methodologies you use to underpin your work and methods you use in order to collect data.
If you wish to collect quantitative data you are probably measuring variables and verifying existing theories or hypotheses or questioning them.
This is a common approach and helps you to 'triangulate' ie to back up one set of findings from one method of data collection underpinned by one methodology, with another very different method underpinned by another methodology - for example, you might give out a questionnaire (normally quantitative) to gather statistical data about responses, and then back this up and research in more depth by interviewing (normally qualitative) selected members of your questionnaire sample.
For further information see Chapter 8 of by Gina Wisker.
Data is often used to generate new hypotheses based on the results of data collected about different variables.
One’s colleagues are often much happier about the ability to verify quantitative data as many people feel safe only with numbers and statistics.