• Paper

    Assistant Professor Hiroko Yamano and Professor Ichiro Sakata

Research paper on “Latent Mediators in Heterogeneous Communities” published at Scientific Reports

A research paper by Assistant Professor Hiroko Yamano, Professor Ichiro Sakata, and colleagues “Evaluating Nodes of Latent Mediators in Heterogeneous Communities” has been published at Scientific Reports.

The development of information technology enables us to access vast amounts of digital information from around the world. However, we are also exposed to the information bias due to the limited range of interactions on the internet, known as the echo-chamber that amplifies and reinforces the same types of opinions, or the filter bubbles that continue to deliver selected specific types of information. In the system of accessing and recommending information that fits our preferences, it becomes more difficult to obtain perspectives apart from our own communities.

In this paper, we proposed a new network index “PW” to detect the nodes that connect distant communities. Conventionally, the importance of a node in a complex network has been debated from the viewpoint of the amount of information received by the nodes and its neighbors. These approaches are effective to extract apparently significant nodes with many important links. However, another method is required to find rare nodes with a few important links. By incorporating the distance between communities connected by nodes, we have successfully evaluated the rarity of nodes.

Network indicators are frequently used in policy science and social science analysis. For example, the network indexes of within-cluster degree Z measures the number of links a node has in its community (“Hubs”), and participation coefficient P measures the number of communities a node connects in the network (“Connectors”). Professor Sakata’s laboratory has applied these indexes to the analyses of the characteristics of firms and regional clusters. The achievements have been officially used at the Regional Economy Society Analyzing System (RESAS) by the Cabinet Office of Japan, and to select the leading companies of the future of the regions by the Ministry of Economy and Industry. The works were also included in the 2014 White Paper on Small and Medium Enterprises in Japan.

However, the participation coefficient P used in this framework cannot adequately reflect the community diversity. To solve this problem, we noted not the numbers but the qualities of the company transactions. We proposed the new index PW, evaluating companies that bring diversity to the community highly. By using this method, it is possible to select candidate companies that play an essential role in innovation activities, which are becoming more open and required to integrate diverse knowledge. Besides, various applications can be considered to create strategies to bring diversity to the community, such as finding people who connect academic groups or research institutions with different expertise and interests.


Evaluating Nodes of Latent Mediators in Heterogeneous Communities

Collaborative Researchers:

Hiroko Yamano, Kimitaka Aratani, Ichiro Sakata


Scientific Reports 10, 8456 (2020).