The measurement of cosmopolitanism, i.e. the feeling of being a citizen of the world and the corresponding openness towards other cultures and peoples, has proved to be challenging and several scholars have questioned its validity. In this paper, we use web probing, i.e. implementing probing techniques of cognitive interviewing in web surveys, to elucidate the meaning of a frequently used direct measure of cosmopolitanism that asks respondents to what extent they feel they are "a citizen of the world". As a single-item measure, it cannot be analyzed by statistical approaches such as confirmatory factor analysis. We compare results from Spain, Denmark, Hungary, Germany, Canada, and the U.S. Though the majority of the respondents show an understanding of the item which corresponds to the intention of the researchers, a large part of them does not. In addition, some country differences in the open answers make sense but other differences between countries are hard to explain. We conclude that asking people to what extent they feel they are "a citizen of the world" does not capture well the concept of cosmopolitanism as used in the literature.
cosmopolitan attitudes; international comparisons; open answers; web probing.