Whereas the nature of epidemiological investigations may lead to a reductionist or limited point of view, medical anthropology provides a more holistic view of the problem and examines the issue from different angles to best understand and help the populations in need. Another critical contribution of medical anthropology has been with regard to critical qualitative data. While epidemiology is focused mainly on quantitative data and trends in health of the population, medical anthropology provides rich source of information on understanding the population's subjective experiences and providing qualitative data explaining why a particular intervention or treatment may have failed among a particular population. Their main contributions in recent years have come from modifying and helping develop epidemiological surveys by taking into account word choice and the "social suitability" of questions, so that responses would be more accurate and thereby helping to increase the validity of the questionnaires. It has also been found that medical anthropologists have played a large role in helping locals better understand the objectives of epidemiologists and thereby helped them become more receptive of their investigations. In addition to all these, one of the major contributions of medical anthropology has come from it's ability to help explain health phenomenon and create and test hypothesis relating to such explanations, in a way that epidemiologists have been unable to due to their strict focus on quantitative data. In short, while epidemiology is good at understanding numerical patterns and biological causes for disease/health conditions, it is unable to fully explain all the factors that underlie certain diseases/health conditions, and this is a gap that medical anthropology has been able to pick up on and complement by providing rich qualitative data which looks at health and diseases from a holistic perspective.