1Department of Preventive Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
2Ulsan Metropolitan City Public Health Policy’s Institute, Ulsan, Korea
3Department of Nursing, Chung-Ang University, Seoul, Korea
4College of Nursing, Sungshin Women’s University, Seoul, Korea
5Department of Preventive Medicine, University of Ulsan College of Medicine, Seoul, Korea
Copyright © 2023 The Korean Society for Preventive Medicine
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
CONFLICT OF INTEREST
The authors have no conflicts of interest associated with the material presented in this paper.
FUNDING
None.
AUTHOR CONTRIBUTIONS
Conceptualization: Pyo J, Lee W, Choi EY, Jang SG, Ock M. Data curation: Pyo J, Ock M. Formal analysis: Pyo J, Ock M. Funding acquisition: None. Validation: Lee W, Choi EY, Jang SG. Writing - original draft: Pyo J, Ock M. Writing - review & editing: Pyo J, Lee W, Choi EY, Jang SG, Ock M.
Characteristics | Quantitative research | Qualitative research |
---|---|---|
Research purpose | Test the validity of the hypotheses established by the researcher to identify the causal relationships and laws of the phenomenon and predict the phenomenon | Discover and explore new hypotheses or theories based on a deep understanding of the meaning of the phenomenon |
Perspective on variables | View factors other than the variables of interest as factors to be controlled and minimize the influence of confounding factors | View factors as natural and accept assessments in a natural environment |
Research view | Objective, outsider view | Intersubjective, insider view |
Data used | Quantifiable, measurable data | Narrative data that can be expressed by words, images and so on |
Data collection method | Primarily questionnaire surveys or tests | Primarily participant observation, in-depth interviews, and focus group discussions |
Nature of data and depth of analysis | Focus on superficial aspects of the phenomenon by using reliable data obtained through repeated measurements | The aim is to identify the specific contents, dynamics, and processes inherent within the phenomenon and situation using deep and rich data |
Strengths and weaknesses | High reliability and generalizability | High validity |
Difficulties with in-depth analysis of dynamic phenomena that cannot be expressed by numbers alone; difficulties in interpreting the results analyzed by numbers | Weak generalizability; interjection of subjectivity of the researcher is inevitable |
Sampling method | Explanation |
---|---|
Typical sampling | Selecting the most typical environment and people for the research topic |
Unique sampling (extreme case sampling) | Selecting unique and uncommon situations or subjects who satisfy the research purpose |
Maximum variation sampling | Selecting subjects showing maximum variation with a target population |
Convenience sampling | Selecting subjects who can be sampled most conveniently considering practical limitations, such as funding, time, and location |
Snowballing sampling | Selecting key research participants who satisfy the criteria established by the researcher and using their recommendations to recruit additional research participants |
Classification | Specific method | Characteristics |
---|---|---|
Level of structuralization | Structured interview | Data are collected by asking closed questions in the order provided by highly specific interview guidelines |
Useful for asking questions without omitting any details that should be checked with each research participant | ||
Leaves little room for different interpretations of the participant’s responses or expressing original thoughts | ||
Semi-structured interview | Between a structured and unstructured interview; interview guidelines are developed in advance, but the questions are not strictly set and may vary | |
The most widely used data collection method in qualitative research, as it allows interviews to be conducted flexibly depending on the characteristics and responses of the participants | ||
Researcher bias may influence the interview process | ||
Unstructured interview | The interview is conducted like a regular conversation, with extremely minimal prior information about the research topic and adherence to interview guidelines to exclude the intention for acquiring information needed for the research | |
Can obtain rich and realistic meaning and experiences of the research participants | ||
The quality of information acquired and length (duration) of interview may vary depending on the competency of the interviewer, such as conversational skills and reasoning ability | ||
Sample size | One-on-one in-depth interview | Excluding cases in which a guardian must accompany the research participant, such elderly or frail patients and children, a single participant discusses the research topic with one to two researchers during each interview session |
This data collection method is recommended for research topics that are difficult to discuss with others and suitable for obtaining in-depth opinions and experiences from individual participants | ||
The range of information that can be acquired may vary depending on the conversational skills and interview experience of the interviewer and requires a relatively large amount of effort to collect sufficient data | ||
Focus group discussion | At least 2 (generally 4–8) participants discuss the research topic during each interview session led by the researcher | |
This method is effective when conducting interviews with participants who may be more willing to open up about themselves in a group setting than when alone, such as children and adolescents | ||
Richer experiences and opinions can be derived by promoting interaction within the group | ||
While it can be an effective data collection method, there may be some limitations in the depth of the interview; some participants may feel left out or not share their opinion if 1 or 2 participants dominate the discussion | ||
Interview method | Face-to-face | The interviewer personally meets with the research participant to conduct the interview |
It is relatively easy to build rapport between the research participant and interviewer; can respond properly to the interview process by identifying non-verbal messages | ||
Cannot conduct interviews with research participants who are difficult to meet face-to-face | ||
Non-face-to-face | Interview between the interviewer and research participant is conducted through telephone, videoconferencing, or email | |
Suitable data collection method for topics that deal with political or ethical matters or intimate personal issues; in particular, email interviews allow sufficient time for the research participant to think before responding | ||
It is not easy to generate interactions between the research participant and interviewer; in particular, it is difficult to obtain honest experiences through email interviews, and there is the possibility of misinterpreting the responses |