# A Bibliometric Overview of Twitter-Related Studies Indexed in Web of Science
## 2 Literature Review
### Methodological Background  
For fully completing our research aim, an in-depth bibliometric analysis is going to be applied. Bibliometric analysis is a useful method for measuring the scientific impact, influence and relationships of the published academic works in a certain research framework [24]. Due to the huge amount of scientific literature, manually organizing results within a specific subject under a giant database becomes unfeasible; hence, scientific measurement technique was considered a viable approach for obtaining a detailed overview of a large bibliographic information [25; 26]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Title** & **Author** & **Year** & \begin{tabular}{c} **Domain and Research** \\ **Focus** \\ \end{tabular} & \
\begin{tabular}{c} **Reference** \\ **Pointer** \\ \end{tabular} \\ \hline A bibliometric analysis on Twitter Research & [PERSON]; [PERSON] & 2014 &
\begin{tabular}{c} Bibliometric study. Argued \\ that political issues are one \\ of the core subjects in \\ Twitter research. \\ Social dynamics. Using \\ Twitter as a communication \\ tool in regional social \\ movements. \\ Social dynamics. Twitter as a \\ mediator in news freedom \\ online movements. \\ Social dynamics. Twitter as a \\ platform to engage \\ individuals in social \\ campaigns and \\ sociochemical social \\ movements. \\ Politics. Political elites use \\ Twitter as a campaign \\ platform in general elections \\ Politics. Using Twitter \\ content to evaluate the \\ impact of different electoral \\ strategies in political \\ politics. The role and \\ importance that Twitter and \\ other social media played in \\ political elections. \\ Geographical information \\ system and disaster \\ management. Using Twitter \\ data to monitor natural \\ disasters and to evaluate the \\ post-effect of such \\ catastrophe \\ Traffic and management. \\ Twitter as a monitor to \\ detect traffic events \\ Politics. Using Twitter \\ content to predict political \\ event \\ Economics. Using Twitter \\ content to predict stock \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary table of the reviewed scientific literature. In bibliometric studies, two main procedures are contained: _performance analysis_ and _science mapping_[27; 28]. Performance analysis enables the evaluation of scientific publication and citation structures on the basis of bibliographic data such as author(s), author affiliation(s) (university, department), academic journal, conference and country, etc., as well as the impact of their activities on the basis of those data [29; 30]. Science mapping displays structural and dynamic aspects of scientific research, which can be generated by the visualization function of digital bibliometric tools [27; 31]. Corresponding to our objectives, performance analysis serves for describing the current environment of Twitter studies (e.g., annual scientific production, most productive authors etc.) Science mapping will allow us to illustrate the collaboration structure between countries, the main themes of Twitter-related studies and their evolution over time. There are different ways to analyze and visualize the research topics of an academic subject; one of them is thematic map. It was first proposed by [PERSON], [PERSON] and [PERSON] [32], and is a coordinate system consisting of centrality (x-axis) and density (y-axis). According to them [32] \"centrality measures for a given cluster the intensity of its links with other clusters, the more numerous and stronger are these links, the more this cluster designates a set of research problems considered crucial by the scientific or technological community\" (p. 164), while \"density characterizes the strength of the links that tie the words making up the cluster together. The stronger these links are, the more the research problems corresponding to the cluster constitute a coherent and integrated whole\" (p. 165).