This article was suitably titled "Being Black is bad for Your Health". In the article, the authors compared two communities; one being an affluent white neighborhood and the other being a primarily poor black neighborhood.
For example, anthropologist, Sharon Traweek (1988) compared two communities of high energy physicists by asking "how they have forged a research community for themselves, how they turn novices into physicists and how their community works to produce knowledge".
Briefly, to compare two communities, 16S sequences for the two are aligned on a common phylogenetic tree, and the branch length unique to each community computed.
For the IDEFICS study it was therefore decided to compare two communities, an intervention and a control region, with a similar socio-demographic and socio-economic structure.
The Positive Action for Today's Health (PATH) trial compares three communities that are randomly assigned to different levels of an environmental intervention to improve safety and access for walking in low income communities.
In this study comparing two neighboring communities, we observed that middle-school students were more likely to be overweight or obese if residing in a community with fewer resources.
The study used a quasi-experimental design comparing seven study communities and seven comparison communities in Nyanza Province and Western Province.
Comparing two approaches to community development would be possible in a randomized trial with communities as the unit of study, and the degree of goal achievement as the outcome.
The causal role of legal ownership is isolated by comparing two geographically close and demographically similar communities in Osasco, a town of 650,000 people in the São Paulo metropolitan area, where some residential units were allocated property titles and others were not.
Specifically, he compared two agricultural communities, one dominated by larger industrialized farms with absentee ownership and a high percentage of hired farm labor, and the other community was dominated by smaller owner-operated farms.
