The problem of adequate validity or reliability is a major criticism. Because of the subjective nature of qualitative data and its origin in single contexts, it is difficult to apply conventional standards of reliability and validity. For example, because of the central role played by the researcher in the generation of data, it is not possible to replicate qualitative studies. Also, contexts, situations, events, conditions and interactions cannot be replicated to any extent nor can generalisations be made to a wider context than the one studied with any confidence
The data that will serve as the basis for explaining a phenomenon, therefore, can be gathered through surveys. Such surveys use instruments that require numerical inputs or direct measurements of parameters that characterize the subject of investigation (. pH, dissolved oxygen, salinity, turbidity, and conductivity to measure water quality). These numbers will then be analyzed using the appropriate statistical application software to unravel significant relationships or differences between variables. The output serves as the basis for making the conclusions and generalizations of the study.