手法を比較

	質的研究概観	データ収集方法
分野	研究方法論	研究方法論
系統	Process / pipeline	Process / pipeline
提唱年	1900	1980
提唱者	Ethnographers (Boas), grounded theorists (Glaser & Strauss, 1967), phenomenologists, and interpretivists (1900s–1980s)	Floyd Fowler (surveys); John Creswell, Robert DeVellis (qualitative and scale methodology)
種類	Framework	Framework
原典	Creswell, J. W. (2017). Qualitative Inquiry and Research Design: Choosing Among Five Approaches (4th ed.). SAGE Publications.	Fowler, F. J. (2014). Survey Research Methods (5th ed.). SAGE Publications.
別名	qualitative inquiry, exploratory research, interpretive research	data gathering, measurement instruments
関連	3	3
概要	Qualitative research is a systematic inquiry into human experiences, meanings, behaviors, and contexts using non-numerical data (words, text, images, observations). Unlike quantitative research, which seeks to measure variables and test hypotheses numerically, qualitative research prioritizes depth, contextual richness, and understanding of 'how' and 'why.' Major approaches include phenomenology (lived experiences), grounded theory (theory development from data), ethnography (cultural understanding through immersion), case study (in-depth investigation of a specific case), and narrative inquiry (personal stories). Creswell (2017), Braun and Clarke (2006), and Patton (2015) provide contemporary frameworks for qualitative design, data collection, and analysis.	Data collection methods are the specific techniques and instruments used to gather information from research participants or sources. Common quantitative methods include surveys (questionnaires, interviews), physiological measurements (blood pressure, lab assays), behavioral observations, and administrative/secondary data (e.g., medical records, national registers). Qualitative methods include in-depth interviews, focus groups, observations, and document analysis. Selection and design of data collection instruments directly affect data quality, validity, and reliability. Floyd Fowler's work on survey methodology (1980s–2010s), Robert DeVellis's scale development approach, and John Creswell's frameworks for qualitative data collection provide systematic guidance.