STUDY ON THE METHODS OF IDENTIFICATION

STUDY ON THE METHODS OF IDENTIFICATION AND JUDGEMENT FOR OPINION LEADERS IN PUBLIC OPINION
LIU YIJUN
Institute of Policy and Management, Chinese Academy of Sciences, Beijing 100190, China
Center for Interdisciplinary Studies of Natural and Social Sciences, Chinese Academy of Science, Beijing 100190, China
E-mail: yijunliu@casipm.ac.cn
TANG XIJIN GU JIFA
Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190
Center for Interdisciplinary Studies of Natural and Social Sciences, Chinese Academy of Science, Beijing 100190, China
E-mail: jfgu@amss.ac.cn
During the process of opinion evolution, the individuals look for emotional support and depend on opinion leaders complying with “psychological balance” principle and “Emotional resonance” principle. That is the root cause of generation of opinion leaders. This paper adopts meta-synthetic approach (MSA) and social network analysis (SNA) to identify and judge the opinion leaders and master their behaviors and traces for further exploring the nature of opinion and then effectively controlling and guiding opinion.
1. Introduction
Opinion leaders refer to the individuals who can informally influence other people's attitudes or change their behaviors. The mass media often influence audience and then change their attitudes and behaviors through interpersonal relations. Opinion is basically transmitted from the mass media to opinion leaders, and in turn to people who the leaders want to influence, which is well-known as secondary communication theory (Chen, 1999). Opinion leaders can be treated as audience and also leaders to influence audience. The special position of opinion leaders during opinion evolution process builds their enormous force.
The main effects of opinion leaders include analysis of social problems by critical thinking mode, integration of different public awareness and the dispersive views and awaking people's consciousness. This evaluation not only pointed out the direction of ethos but also judged the different views to overcome some misconception of the public. Once the public summarized their views, they will be infected by faith and passion and become followers of a certain opinion (Liu, 2002). Therefore, opinion leader is always viewed as announcer, persuader and prover.
In general, opinion leaders have the following characteristics, belonging to the same group as general members with many same attributes even the leaders owned the special status because of their knowledge and capacity, keeping in more touch with various sources of information and outside environment than other audiences and acting as sources of information and leading role of other members in a certain area.
Due to the "psychological balance" and "Emotional resonance" principles (Liu and Gu, 2008; Liu, Niu and Gu, 2009) in the social behavior entropy theory (Niu, 2001), the public continually look for the emotional support and depend on opinion leaders. That is the root cause of generation of opinion leaders.
Hegselmann etc al. (2002) figured out that opinion can be formed in a group as small as a few experts or as large as in the whole society. Based on this viewpoint, Section II of this paper will use meta-synthetic approach (MSA) and expert mining (EM) to identify and judge “expert leaders” during the process of experts argumentation. In section III, social network analysis (SNA) will be involved to find out the “opinion leaders” during the opinion formation and evolution over network. Conclusion and the future works will be proposed in Section IV.
2. Identify Opinion Leaders based on MSA
Social public opinion is a complex system. Identifying the opinion leaders emerged in the individuals mass behaviors during the evolution of public opinion is further a complex systems engineering. So this paper adopts meta-synthetic approach as a directional and advanced way to guide the identification of opinion leaders.
2.1. Meta-synthetic Approach and Expert Mining
MSA, proposed by a Chinese system scientist Qian Xuesen (Tsien HsueShen), is one of the system methodologies to tackle with open complex giant system (OCGS) problems from the view of systems in the early 1990s (Qian, Yu and Dai, 1990). Here, we regarded OCGS problems such as social public opinion as ill-structured or wicked problems. This approach expects to unite organically the expert group, data, all sorts of information, the computer technology, and even scientific theory of various disciplines and human experience and knowledge for proposing hypothesis and quantitative validating. Later it is evolved into Hall of Workshop for Meta-Synthetic Engineering (HWMSE) which emphasizes to make full use of breaking advances in information technologies (Gu and Tang, 2003; Gu and Tang, 2005).
Expert mining (EM), as a new mining method, is put forward based on the meta-synthetic approach (Gu, 2006; Gu, Song and Zhu, 2008). This method emphasizes expert experience, ideas and wisdom mining. It is not built on the basis of mass data but in a smaller group of samples based on the thinking of experts to conduct in-depth experience in mining. This method is also different from those based on artificial intelligence-based expert system because it focuses more on people - machine, human-oriented to people's wisdom and the wisdom of the main groups. Mining expert system methodology, which combines science, scientific thinking and knowledge of scientific theories and makes full use of modern computer technology, is the development of the former theory and technology.
This section tries to identify and judge expert leaders by expert leader judgment module with guidance of MSA and EM.
2.2. Hall for Workshop of Expert Argumentation and Expert Leader Judgement Module
Based on MSA, expert mining method and knowledge creation model, the Hall for Workshop of Expert Argumentation is to provide a distributed computer platform. On which, participants bring out new ideas and knowledge through communication and collaboration (Tang and Liu, 2004; Liu and Tang, 2005). The Hall integrates proposals and views from experts to build solution and compute quantitatively degree of centralization and consensus.
Aiming to the discussion topic, the Hall for Workshop of Expert Argumentation expresses the registered ID (shown in rectangular box) and keywords (shown in ellipse box) as a visualized two-dimensional map, as shown in Figure 1, The experts owning high degree of concerns will be centralized. This provides a new way to share knowledge and solve unstructured problems.
Discussion space is a joint thinking space for the participants. Via the 2-dimensional space, the idea association process to stimulate participants’ thinking, idea generation, tacit knowledge surfacing and even wisdom emergence is exhibited based on the utterances and keywords from participants. The global structure and relationships between participants and their utterances are shared by all participants in the session. It helps the user acquire a general impression about each participant’s contributions toward the discussing topic, and understand the relationships of each thinking structure about the topic between participants.
The expert leader judgement module of the Hall for Workshop of Expert Argumentation constructs the consistent matrix based on the sameness and difference of keywords from all participants. The largest eigenvector will be computed to achieve sort of speaker. The sort can also be used to exhibit contribution of each participant (Tang and Liu, 2004). The matrix A can be expressed as,
and . (1)
Where, represents the set of keywords from no. i participant.
After discussion, participants will be evaluated to help analyze quantitatively discussion result and try to find out key speaker based on effects on group from each participant. Those key speakers are “opinion leader”.
2.3. Example analysis
The Xiangshan Science Conference (XSSC, www.xssc.ac.cn), which is initiated in 1993 in similar to Gordon Research Conferences and denotes as the general designation of a series of small-scale academic meetings which bring together a group of scientists working at the frontier of research of a particular area and enable them to discuss in depth all aspects of the most recent advances in the field and to stimulate new directions for research, is a top-level science forum for interdisciplinary and cutting-edge studies and can be viewed as a platform for knowledge sharing and creation in China. Next we apply our tool to analyze Xiangshan Science Conference.
Figure 1 shows the process and result map of analyzing "the brain, consciousness and intelligence" topic with experts meeting system (Liu and Tang, 2005). Detail of design and development of the system will not be explained here. Figure 1(b) is different from Figure 1 because one new expert (“Pan”) is added into the discussion. But the two maps own the same character that the expert "Wang Yunjiu" locates at the center of the discussion. That indicates that he actively involved in the "brain" research and relative meeting. This result can be verified by the record in text mode from Xiangshan Conference.












Figure1 (a) Figure1 (b)
Figure 1. Two-dimensional Distribution of Participants and Keywords
Table 1 lists the evaluation of participation based on agreement and discrepancy matrixes. It is shown that user holds highest rank based on both eigenvectors, which may be justified by his active role as one of chairpersons or plenary speech contributors among those conferences, which furthermore exposes his big influence in neuroscience field in China.
Table 1. Evaluction of 9 Participantions
Maximum eigenvector of agreement matrix: (0.3761, 1.0914, 0.3082, 0.6179, 0.2522, 0.3618, 0.3125, 0.1937, 0.1092 )
Rank of the top five participants: > > > >

Due to less staff and simple content, Prof. Guo can not be defined as “opinion leader”. Instead, “leader expert” is better. However, such a new idea builds an important basis for research of identifying “opinion leader”.
The social network analysis proposed in the following section of this article can be used to identify “opinion leaders" from a large scale of participants.
3. Detect opinion leader based on SNA
3.1. SNA
Social network analysis (SNA), as a new paradigm for sociological research (Liu, 2004; Luo, 2005), is proposed in 1930s and enhanced in 1970s. This article intends to detect the “opinion leaders” by this method. In fact, the opinion leaders are those special individuals who appear during the formation of opinion from microcosmic individual actions to macroscopical group behavior.
“Social network” refers to the social actors and the collection of the relationship between different actors. That is, a social network is a collection of a number of points (social actors) and the connection between the points (the relationship between actors). “Social network” emphasizes that each actor has a certain extent relationship with other actors. Social network analysis build models for these relationships, try to describe the structure of relations between group members and study the effect on group and individual from this structure.
Social network analysis can be used to identify quantitatively the “opinion leaders” because this approach has exactly described the relationship between the subjects of opinion in a very good way. In which, the social network position refers to a series of individual actors who have the similar characters in social activities, relationship and interaction located in the same relationship network, network factor refers to combination of relations to link the social positions and mode of the relation between the actors or positions.
Some other concepts such as point, edge, degree, betweenness, cutpoint, component, subgroup and centralization and so on are involved in SNA. During the formation and evolution of opinion, this article particularly concerns the "cutpoint".
3.2. Cutpoint
In graph theory, the only one point connecting two sub-graphs is called as cutpoint. The cutpoint is very important because its absence will divide network into independent segments named after block. Such a point is important to not only network but also the other point That is, cutpoint plays the "opinion leaders" role among the subjects of opinion.
3.3. Example analysis
A series of serious terrorist attacks occurred in the in the eastern part of United States at September 11, 2001. With this incident, World Trade Center in New York, the Pentagon where U.S. Department of Defense locates in Washington and some other important buildings had been attacked and heavy casualties were caused. By the later survey, this is an organized and purposeful terrorist activity against the interests of the people, the U.S. security and even world peace. After that, not only the United States governments but also experts around the world analyze this incident in-depth for getting more meaningful and valuable information and forecasting such terrorism. Figure 2 (http://www.orgnet.com/tnet.html) shows the social network analysis of key man of 9 • 11 terrorist events.























Figure 2 Social network analysis of participants of 9 • 11 terrorist events

This case is involved here to indicate that social network analysis is a good method and technique to identify the “key persons”. Analogously, opinion leader can be easily identified in a war of opinion through the "cut point" algorithm if the network topology of opinion subjects had been built out.
Nie et al (2005) have analyzed the relationship between scientific collaborators (385 articles and 192 authors produced from different NSFC major research) through social network analysis and found out the "expert leaders" of the network of scientific cooperation with cut-point algorithm.
4. Conclusions
Due to the “psychological balance” and “Emotional resonance” principles, the public continually look for the emotional support and depend on opinion leaders. That is the root cause of generation of opinion leaders. In this paper, MSA and SNA are involved to identify the opinion leaders and master their behaviors and traces for further exploring the nature of opinion and then effectively controlling and guiding opinion.
Opinion leaders play the key roles in the process of guiding opinion. Trend of opinion would be obviously affected through intervening and controlling opinion leaders. In future, intervening of opinion leaders during formation and evolution of opinion by soft control theory will be studied in-depth.
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