MOSAiCH is a cross-sectional survey that focuses on the Swiss population’s values and attitudes towards a wide range of social issues. The thematic focus of the 2023 edition lies on National Identity and Citizenship, defined by the 2023 module of the International Social Survey Programme (ISSP) which is a combination of the earlier National Identity and Citizenship Modules (http://www.issp.org). This international part is supplemented by selected socio-demographic questions, as well as a module composed of questions specific to Switzerland. The questions of this Swiss part are selected through a public call, either expanding the ISSP module thematically or measuring other dimensions that are of special interest to Switzerland. Topics: - National Identity and Citizenship (ISSP 2023), including international optional questions - Sociodemographics (education, work, income, household composition, religion, nationality, etc.) - Questions from 4 different proposals from the call on: 1) Immigration Misperceptions: Exploring their nature and drivers 2) Intentionalism in Sociological Attitudes towards Immigrants 3) Nationalism, Identification to one’s country, and Meaning in life 4) National and Supranational Collective Narcissism, Identity, and Immigration Attitudes.