This book addresses the methodological features of cross-cultural research. The common characteristic of such studies is their comparative nature, which involves the comparison of at least two cultural populations. Many studies involve different nation states, in sociology (e.g., Inglehart & Welzel, 2010; Van Deth, Montero, & Westholm, 2007), education (e.g., Arnove, Torres, & Franz, 2012; Van de Werfhorst & Mijs, 2010), political sciences (e.g., Coffé & Bolzendahl, 2010; Poguntke & Webb, 2007), management (e.g., House et al., 2004), and psychology (e.g., Schmitt, Allik, McCrae, & Benet-Martínez, 2007). However, comparative studies can also involve different ethnic groups from a single country such as the comparison of ethnic groups in the United States (e.g., Trinidad, Pérez-Stable, White, Emery, & Messer, 2011) and in Europe (Phalet & Kosic, 2006).