Last update:
29-Apr-2026

The most common methods of data collection in qualitative research are interviews, focus groups, observation, and Delphi methodology. Interviews are used to explore in depth individuals' opinions, experiences, feelings, perceptions, beliefs, and motivations regarding specific issues. Interviews are divided into structured, semi-structured and unstructured, with semistructured interviews being used more often. Focus groups are a common method of data collection in qualitative research, in which a group of individuals discuss a specific research topic under the supervision, organization and guidance of a coordinator or, in other words, a facilitator. Focus groups are used to extract information in a collective form and find the interpretations behind this information. In addition, focus groups are used to gain an in-depth understanding of participants' views, experiences, and beliefs at an overall level. Observation in qualitative research usually refers to the observation of individuals (and or events) and is the systematic observation of individuals (and or events) to investigate their behaviors and interactions in their natural environment. Observation is divided into (a) direct observation in which the researcher observes the studied subjects without interacting with them in the study area and (b) participatory observation in which the researcher observes the studied subjects on the one hand and interacts with them in the study area on the other, i.e. acts as both an observer and a participant. The Delphi methodology is a method of agreement or, in other words, consensus and aims to find a general agreement of the views of a group of experts on a particular topic. In particular, it is used in research to solve problems, create research hypotheses and set priorities, while the way agreement is determined may vary from study to study depending on the research subject.

Key words: Delphi methodology, Focus groups, Interviews, Observation, Qualitative research.