Longitudinal:
What Is Longitudinal Data?
Longitudinal data, sometimes called panel data, is a data that is collected through a series of repeated observations of the same subjects over some extended time frame – and is useful for measuring change. Longitudinal data effectively follows the same sample over time, which differs fundamentally from cross-sectional data because it follows the same subjects over some time, while cross-sectional data samples different subjects (whether individuals, firms, countries, or regions) at each point in time. Meanwhile, a cross-sectional data set will always draw a new random sample.
Longitudinal data is used widely in the social sciences, including among economists, political scientists, and sociologists. [Investopedia]
Noted in “Tech companies are finally being shamed into action,” Jennifer Rubin, WaPo:
Considerable thought has already gone into this concept [of civil society applying pressure on social media companies]. The Commission on the Practice of Democratic Citizenship, put together by the American Academy of Arts & Sciences, recently included several suggestions in its report for bolstering American democracy: “Form a high-level working group to articulate and measure social media’s civic obligations and incorporate those defined metrics in the Democratic Engagement Project”; tax digital advertising to “support experimental approaches to public social media platforms as well as local and regional investigative journalism” (think of it as PBS or C-SPAN for the Internet); and start a new project to “conduct a focused, large-scale, systematic, and longitudinal study of individual and organizational democratic engagement” in the context of digital media. Others want to use antitrust laws to limit the reach of tech behemoths.
My bold.
