So sánh phương pháp

	Phương pháp thu thập dữ liệu	Các Phương Pháp Lấy Mẫu Trong Nghiên Cứu
Lĩnh vực	Phương pháp luận nghiên cứu	Phương pháp luận nghiên cứu
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1980	1950
Người khởi xướng	Floyd Fowler (surveys); John Creswell, Robert DeVellis (qualitative and scale methodology)	William G. Cochran and Leslie Kish (1950s–1970s)
Loại	Framework	Framework
Công trình gốc	Fowler, F. J. (2014). Survey Research Methods (5th ed.). SAGE Publications.	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). John Wiley & Sons.
Tên gọi khác	data gathering, measurement instruments	sampling strategy, sampling design, probability and non-probability sampling
Liên quan	3	3
Tóm tắt	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.	Sampling is the process of selecting a subset of individuals, observations, or units (the sample) from a larger population to study. Sampling methods are broadly classified into probability (random) and non-probability (non-random) approaches. Probability methods—random sampling, stratified sampling, cluster sampling, systematic sampling—enable statistical inference to the population and allow calculation of confidence intervals and margins of error. Non-probability methods—convenience, purposive, snowball, quota sampling—are practical for exploratory or qualitative research but do not support formal statistical generalization. Cochran's Sampling Techniques (1977) and Kish's Survey Sampling (1965) are foundational references; modern applications span surveys, experiments, qualitative studies, and clinical trials.