I believe that the research observations about the sexual behaviour of a group of high-schoolers can be seen as characteristic of an interpretive methodology.
The scientific methods of an interpretive sociologist include unstructured interviews, observation and analyses of the participants' behaviour and inclusion of personal documents. On the other hand, the positivist methodology includes social surveys, formal questionnaires and official and reliable statistical analysis. Positivist research needs to be reliable, accurate and representative. In this case, the sexual behaviour of this group is analyzed based on the interpretive methodology, without social surveys and questionnaires that represent the entire adolescent population. The focus of the research is on a small group and the results cannot be taken as representative, reliable and applicable to a bigger population.