In research on the social capital of individuals, there has been little standardisation of measurement instruments, and more emphasis on measuring social relationships than on social resources. In this paper, we propose two innovations. First, a new measurement method: the Resource Generator; an instrument with concretely worded items covering 'general' social capital in a population, which combines advantages of earlier techniques. Construction, use, and first empirical findings are discussed for a representative sample (N = 1004) of the Dutch population in 1999-2000. Second, we propose to investigate social capital by latent trait analysis, and we identify four separately accessed portions of social capital: prestige and education related social capital, political and financial skills social capital, personal skills social capital, and personal support social capital. This underlines that social capital measurement needs multiple measures, and cannot be reduced to one total measure of indirectly 'owned' resources. Constructing a theory-based Resource Generator is a challenge for different contexts of use, but also retrieves meaningful information when investigating the productivity and goal specificity of social capital. © 2004 Elsevier B.V. All rights reserved.