Health research: referes to the types of scientific investigations that aim to test ideas, answer questions, improve treatment options and increase knowledge about human health. Mixed methods: combines quantitative and qualitative methods. Quantitative methods: experimental studies : studies preventions and treatments for diseases. Investigator activelty manipulates which groups received the agent under study: main types : randomized and non randomized, observational studies: studies cases, preventions and treatments for diseases. Investigator passively observes as nature takes its course: makes causal inferences about the association between exposure and disease, types: descriptive and analytic. Qualitative research: studies that aim to explore perceptions or views using text or narrative ( qualitative) Wide range of approaches: exploratory interviews, focus groups, observation, conversation, discourse and narrative analysis, documentary and video analysis. Mixed methods research: researchers collect and analyse both quantitative and qualitative data within the same study. Mixing of methods during data collection, data analysis and interpretation of the evidence.