A distinction has recently been proposed between bridging (or encompassing) and bonding (or inward-looking) social networks. However, existing theoretical contributions remain vague as to the fundamental meaning of both concepts. As a consequence, two distinct interpretations have developed alongside each other. In the present paper, we employ data on voluntary association membership in Flanders to empirically illustrate that both approaches can lead to substantially different outcomes and therefore appear to tap into different dimensions of bridging versus bonding. These findings underline the problematic nature of the current conceptual ambiguity. We conclude that should the bridging/bonding distinction add meaningfully to our understanding of the external effects of social networks, it is essential to resolve the conceptual and methodological imprecision.