In a previous post, I introduced the idea of stability analysis for selecting the number of clusters in a data set. Applications of these techniques have been largely confined to the bioinformatics domain. However, the general concepts are applicable elsewhere. In text mining, topic modeling refers to a broad set of techniques for discovering the [...]
A frequent question that arises when applying unsupervised learning methods, such as cluster analysis or topic modeling, is “how many clusters are in my data set”? While domain knowledge can often help to narrow down this choice to a smaller range, choosing one or more specific values of the number of clusters k often presents [...]
Recently I presented a tutorial at the VOX-Pol project’s inaugural Summer School in DCU, which covered practical analysis and visualisation of social networks. Since 2010, my application of choice for visualising networks has been the excellent open source Java-based Gephi Platform, developed by Mathieu Bastian and his colleagues. The three screen overview/tabular/preview interface fits well [...]
In 2011, at the ICWSM conference in Barcelona we presented the first quantitative analysis of the Irish blogosphere, working with Karen Wade from the Humanities Institute of Ireland (HII). Since then, there has been considerable change in the use of blogs, particularly with the rapidly increasing popularity of microblogging platforms such as Twitter. In September [...]
In my previous post, I described the collection and initial characterisation of a new dataset, consisting of user curated lists of movies originating from IMDb. Here I provide a more in-depth analysis of the data, by applying techniques from social network analysis and bibliographic analysis to discover latent patterns of movies within the aggregated list [...]
User content curation is becoming an important source of preference data, as well as providing information regarding the items being curated. One popular approach involves the creation of lists of items. This is facilitated on a range of sites, from lists of users on Twitter to lists of locations on Foursquare. In previous work, I [...]
This morning the British and Irish Lions Rugby Union squad to tour Australia was announced, with plenty of discussion on Twitter (#lionstour, #lions2013). It was interesting to see that, within a few minutes of the announcement, a number of Twitter user lists had already been curated, referring to the official Twitter accounts of players and staff [...]
On Friday I will be presenting some recent network analysis work from Clique at the ACM Web Science conference in Paris (WebSci’13). In many social networks, several different types of relations will exist between the same set of users. For example, a Twitter user can be represented by the words in their tweets, the URLs [...]