手法を比較

	定量的内容分析	縦断的定量的内容分析
分野	研究デザイン	研究デザイン
系統	Process / pipeline	Process / pipeline
提唱年	1950s (Berelson 1952; Krippendorff 1980/2004)	1950s onward; longitudinal application widely adopted in media research by the 1970s–1980s
提唱者	Bernard Berelson; later systematised by Klaus Krippendorff	Developed within communication and media studies; codified by Berelson (1952) and extended by Riffe, Lacy, Fico
種類	Quantitative observational research method	Quantitative observational research design
原典	Krippendorff, K. (2004). Content Analysis: An Introduction to Its Methodology (2nd ed.). Sage. ISBN: 978-0761915454	Riffe, D., Lacy, S., Watson, B., & Fico, F. (2019). Analyzing Media Messages: Using Quantitative Content Analysis in Research (4th ed.). Routledge. ISBN: 9781138490536
別名	QCA, manifest content analysis, systematic content analysis, frequency-based content analysis	longitudinal content analysis, repeated-measure content analysis, time-series content analysis, longitudinal QCA
関連	4	5
概要	Quantitative content analysis is a systematic, replicable method for converting the manifest content of text, images, or other recorded communication into numerical data. By applying a pre-specified codebook to a defined corpus and counting or scaling the resulting categories, researchers obtain frequency distributions, proportions, and relationships that can be subjected to standard statistical tests. It is the dominant method for large-scale, objective analysis of media, documents, social media posts, policy texts, and similar materials.	Longitudinal quantitative content analysis systematically codes and counts features of texts, images, or media messages gathered at two or more points in time, enabling researchers to track how content changes, how themes rise or fall in prevalence, and how media or institutional messaging responds to external events. The design merges the structured measurement logic of quantitative content analysis with the temporal tracking power of longitudinal observation.