Topics in Periodicals from the Swedish Diabetes Association 1949 – 1990: Extending the Topic Modelling Tool Topics2Themes with a Timeline Visualisation

Abstract

Existing methods for visualising temporal topic models typically present the information in an aggregated form, and do not offer any possibility to track the specific texts responsible for the change in topic prevalence over time. We present a new type of topic modelling-based timeline visualisation. It still provides an overview with aggregated topic information suitable for distant reading, while also allowing the user to gradually zoom into the image for more detail. At the most detailed level, the individual texts can be reached, which makes it possible to switch to close reading. The timeline visualisation was implemented as an extension of the topic modelling tool Topics2Themes, but this visualisation technique can be adapted to other topic modelling tools and algorithms. We showcase the timeline visualisation on a corpus of periodicals from the Swedish Diabetes Association, which is one of the patient organisation corpora studied within the interdisciplinary project ActDisease. One timeline visualisation was generated for the entire corpus. Additionally, we generated a timeline focusing on the texts that contain the word “dietitian”. The two timelines, including the functionality to zoom into the graphs and reach the texts, were used to analyse the topics and how they vary. It could be concluded that some of the topics and topic timelines were predictable, while others revealed content that might be less expected. These results indicate validity of the method applied, and they also show that this visualisation technique could help us learn something new.