Before implementing the behavioral surveillance survey (PR-NHBS), a series of formative research activities are carried out, through two sources of qualitative information collection: 

• Key informants interviews 

• Focus Groups

The data collected during this preparatory phase provides contextual information about the current dynamics of the population of interest (MSM, PWID, HET) and helps sites where the study is implemented annually to make decisions about field operations and other logistical issues.