手法を比較

	Longitudinal Content Analysis	文書分析
分野	質的手法	質的研究
系統	Process / pipeline	Process / pipeline
提唱年	Mid-20th century onward; systematized alongside content analysis (Berelson, 1952; Krippendorff, 1980)	1920
提唱者	Developed within the content analysis tradition; longitudinal extensions widely applied since the mid-20th century in communication and political science research	Max Weber and Karl Mannheim
種類	Qualitative and mixed-methods research design	Method
原典	Krippendorff, K. (2018). Content Analysis: An Introduction to Its Methodology (4th ed.). Sage. ISBN: 978-1506395661	Scott, J. (1990). A Matter of Record: Documentary Sources in Social Research. Polity Press. ISBN: 978-0745608419
別名	LCA, repeated content analysis, diachronic content analysis, trend content analysis	documentary analysis, textual analysis, content analysis of documents, archival research
関連	5	4
概要	Longitudinal Content Analysis (LCA) applies systematic content analysis to documents, media, or texts sampled at two or more time points in order to detect how themes, frames, language, or discourse patterns change or persist over time. Drawing on the established logic of content analysis, it adds a temporal dimension that allows researchers to chart trends, trace the evolution of representations, and test hypotheses about historical or social change. It is widely used in communication research, political science, media studies, and the health sciences.	Document analysis is a systematic qualitative research method for examining written, visual, or audiovisual sources—such as policy documents, historical records, organizational records, media reports, emails, social media posts, photographs, or videos—to extract meaning, identify patterns, and understand social phenomena. Developed by Weber and Mannheim in early 20th-century sociology, the method bridges historical research, content analysis, and textual interpretation. Document analysis is used across disciplines to understand organizational change, policy evolution, media representation, historical events, and cultural meaning. Documents provide evidence of what organizations, institutions, or societies value, decide, and communicate, often revealing contradictions between policy and practice.