in rural Guinea-Bissau (Boone et al., 2014) and Nigeria (Helen, Fazlur, & Sourav, 2020), but also in high-income countries, such as Norway and the United Kingdom (Dickerson & McIntosh, 2013; Falch, Lujala, & Strøm, 2013).These gaps in access extend to quality. Students in rural areas and small towns of countries at all levels of development perform significantly worse on exams (Bashir, Lockheed, Ninan, & Tan, 2018; Mullis, Martin, Foy, & Arora, 2012). Yet, rural areas are not always disadvantaged across all dimensions. Gagnon & Mattingly (2018) find that U.S. racial and ethnic achievement gaps are smaller in rural areas than those found in city groups.

Variation in educational outcomes across the urban–rural continuum can be explained by several factors, including differences in infrastructure, human resources (e.g., teacher recruitment, monitoring, and skills upgrading), and differing expectations about education from students, families, and policy makers. This variation makes it necessary to go beyond the urban–rural dichotomy, considering social, economic, and other contextual factors, as well as the way they interact with educational processes and outcomes along the continuum (Biddle & Azano, 2016; Burdick-Will & Logan, 2017). Some countries already distinguish school location based on where they are along the urban–rural continuum. One demonstration is the calculation of teacher hardship pay (Pugatch & Schroeder, 2014). In Zambia, schools were classified into four categories, based on distance to the nearest district center. Before that, a more complex formulation incorporated distance to an array of amenities (Chelwa, Pellicer, & Maboshe, 2019). Some high-income countries also distinguish school location based on the full urban– rural continuum, such as the United States (National Center for Education Statistics (NCES), 2020), Australia, and other OECD countries (Echazarra & Radinger, 2019). In OECD’s Programme for International Student Assessment (PISA), students’ exam results are divided into five categories on location of school ranging from villages of fewer than 3,000 inhabitants to large cities of more than 1 million inhabitants.

Strong rural-urban connectivity can also contribute to poverty reduction by facilitating employment opportunities, food security, and access to health and education services through effective inter-scalar relationships. It can also affect institutions. Although rural and urban voters are often portrayed as opposites, differences are best understood as a continuum, not a dichotomy (Lichter & Ziliak, 2017). For instance, despite U.S. rural counties tending to be more conservative, there is variation within these rural areas (Scala & Johnson, 2017). When discussing behaviors or social organization, Lichter & Brown (2011) state very clearly that U.S. spatial and social boundaries are diverging and rural and urban are increasingly interdependent, making it more difficult to discuss social change in rural (or urban) areas without acknowledging the other.

Clearly, rural–urban linkages that produce the urban–rural continuum are important factors for policy makers to take into account when allocating resources or designing programs and must be better mapped and understood. The next section reviews different approaches on how to do so.

# 3. Different mapping approaches

Characterizing the connectedness between rural areas and urban centers can be done from a number of different perspectives. It can be from the standpoint of an urban center, with a geographic scope limited to its immediate rural surroundings, or from the perspective of rural locations and the specific 5