What are “hot” and “cold” topics and how do we identify them?
The amount of scientific interest shown in different topics varies over time. Those generating increasing levels of interest are “hot” topics, while topics with falling levels of interest are “cold” (Antons, 2016).
The level of scientific interest in a topic is reflected by its prevalence in published literature, so analysis of the occurrence of topics in the literature over time can provide an indication of topic dynamics (Griffiths & Steyvers, 2004).Entity linking is an incredibly useful tool for identifying topic occurrence in a body of literature. By taking account of the context in which a concept is mentioned, entity linking can pick up trends which would be missed by analyses based on keywords alone.
Why should researchers care about topic dynamics?
Information about topic dynamics can give us an insight into the ways in which scientific interest in different topics has waxed and waned in the past. This can be useful in historical research. The topic landscape can also be mapped for different journals, allowing researchers to select the most appropriate journals to which they should submit their papers (Lee, 2018).
Further, we can use data on topic dynamics to make predictions about future research trends. We may build predictive models, or we may simply assume past growth to be an indicator of future potential. An understanding of topic dynamics can therefore help researchers and funders to direct research efforts to areas where there is most likely to be demand.
Finding research gaps
Perhaps of greatest interest to potential researchers are hot topics associated with relatively small numbers of published articles. These represent emerging areas of scientific interest and may be the richest source of research gaps, waiting to be filled. However, hot topics already associated with a large body of published work, may still present opportunities to apply different or multiple levels of analysis, while cold topics may represent areas where interest can be revived (Antons, 2016).
Analysis of topic dynamics may also reveal be opportunities to connect related areas of research which have previously been considered separately. Hopp (2018) mapped the topic landscape of disruption research between 1975 and 2016 to discover two increasingly disconnected subnetworks within the field. They suggest that reconnecting these areas should be a research priority.
Technological advances have resulted in the development of excellent tools for analysing the vast bodies of literature available to us. This presents researchers with the opportunity to understand the dynamics of scientific interest, allowing them to direct their work towards the areas where it may have the greatest impact.
Antons, D., Kleer, R. & Salge, T. O. (2016) Mapping the Topic Landscape of JPIM, 1984-2013: In Search of Hidden Structures and Development Trajectories. Journal of Product Innovation Management, 33(6), 726-749.
Griffiths, T.L. and Steyvers, M., 2004. Finding scientific topics. Proceedings of the National academy of Sciences, 101(suppl 1), pp.5228-5235.
Hopp, C., Antons, D., Kaminski, J. & Salge, T. O. (2018) The Topic Landscape of Disruption ResearchA Call for Consolidation, Reconciliation, and Generalization. Journal of Product Innovation Management, 35(3), 458-487.
Lee, H. & Kang, P. (2018) Identifying core topics in technology and innovation management studies: a topic model approach. Journal of Technology Transfer, 43(5), 1291-1317.