I think we make a mistake when we consider that data are qualitative if they come from applying qualitative methods and techniques or if they are collected in qualitative researches. I think we make the same mistake when we consider quantitative all data collected through, for example, questionnaires.
I think we have to consider the qualitative or quantitative character of data looking exclusively at data. Are they numeric? Are they textual or visual?
I think (as Traian Rotariu argues) that quantitative data are numeric and that qualitative data are textual or visual and that we could gather quantitative and qualitative data with each and every method and technique being it qualitative or quantitative.
For example most of the data gathered with questionnaires are qualitative in their primary form: opinions, gender, preferences etc. and just a few are quantitative in their primary form: income, age, children's number etc.