手法を比較

	縦断的定量的内容分析	トレンド調査
分野	研究デザイン	研究デザイン
系統	Process / pipeline	Process / pipeline
提唱年	1950s onward; longitudinal application widely adopted in media research by the 1970s–1980s	Mid-20th century (formalised in social science methodology ~1950s–1960s)
提唱者	Developed within communication and media studies; codified by Berelson (1952) and extended by Riffe, Lacy, Fico	Earl Babbie and survey research tradition
種類	Quantitative observational research design	Quantitative longitudinal research design
原典	Riffe, D., Lacy, S., Watson, B., & Fico, F. (2019). Analyzing Media Messages: Using Quantitative Content Analysis in Research (4th ed.). Routledge. ISBN: 9781138490536	Creswell, J. W. (2014). Research Design: Qualitative, Quantitative, and Mixed Methods Approaches (4th ed.). Sage. ISBN: 978-1452226101
別名	longitudinal content analysis, repeated-measure content analysis, time-series content analysis, longitudinal QCA	trend study, trend survey, longitudinal trend study, time-series survey
関連	5	4
概要	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.	Trend research is a longitudinal quantitative design that tracks changes in a characteristic of a general population over time by surveying different, independently drawn samples at two or more time points. Unlike panel studies, the same individuals are not followed; rather, each wave draws a fresh sample from the same population, allowing researchers to detect population-level shifts in attitudes, behaviours, or conditions while avoiding the attrition and panel conditioning problems of repeated-measures designs.