Estimating semantic networks of groups and individuals from fluency data
One popular and classic theory of how the mind encodes knowledge is an as- sociative semantic network, where concepts and associations between concepts correspond to nodes and edges, respectively. A major issue in semantic network research is that there is no consensus among researchers as to the best method for estimating the network of an individual or group. We propose a novel method (dubbed U-INVITE) for estimating semantic networks from semantic fluency data (listing items from a category) based on a censored random walk model of mem- ory retrieval. We compare this method to several other methods in the literature for estimating networks from semantic fluency data. In simulations, we find that U- INVITE can recover semantic networks with low error rates given only a moderate amount of data. U-INVITE is the only known method derived from a psychologi- cally plausible process model of memory retrieval and one of two known methods that are consistent estimators of this process: if semantic memory retrieval is con- sistent with this process, the procedure will eventually estimate the true network (given enough data). We conduct the first exploration of different methods for esti- mating psychologically-valid semantic networks by comparing people’s similarity judgments of edges estimated by each network estimation method. We conclude with a discussion of best practices for estimating networks from fluency data.