  Shared opinions are an important feature in the formation of social groups.
In this paper, we use the Axelrod model of cultural dissemination to represent
opinion-based groups. In the Axelrod model, each agent has a set of features
which each holds one of a set of nominally related traits. Survey data, for
example, has a similar structure, where each participant answers each of a set
of items with responses from a fixed list. We present an alternative method of
displaying the Axelrod model by representing it as a bipartite graph, i.e.,
participants and their responses as separate nodes. This allows us to see which
feature-trait combinations are selected in the final state. This visualisation
is particularly useful when representing survey data as it illustrates the
co-evolution of cultures and opinion-based groups in Axelrod's model of
cultural diffusion. We also present a modification to the Axelrod model. A
standard finding of the Axelrod model with many features is for all agents to
fully agree in one cluster. We introduce an agreement threshold and allow nodes
to interact only with those neighbours who are within this threshold (i.e.,
those with similar opinions) rather than those with any opinion. This method
reliably yields a large number of clusters for small agreement thresholds and,
importantly, does not limit to single cluster when the number of features grows
large. This potentially provides a method for modelling opinion-based groups
where as opinions are added, the number of clusters increase.
