Tracing Competing Paradigms - Mapping Scientific Frontiers: The Quest for Knowledge Visualization - page 220

Fig. 6.14 The rises and falls of citation profiles of 221 articles across three periods of the AGN

paradigm

called the Very Long Baseline Array , stretching from Hawaii to Puerto Rico. A
few highly cited articles in this period are located in the center of the co-citation
network, including a review article and a demographic article on supermassive black
holes. According to a three-stage agenda for the study of supermassive black holes
(Kormendy and Richstone 1995 ), a demographic article would correspond to the
third stage. The 1998 article by Magorrian and his collaborators is located between
the 1995 agenda article in the center and Ree's article to the right.
It is clear from Fig. 6.14 that the peaks of citation have moved from one period
to another. There was no paradigm in the first period (1981-1990). In other words,
the core literature on this topic is no more than 10 years old. Three strands of
articles appeared in the second period, suggesting the first generation of theories
and evidence. The fall of two groups of citations in the third period and the rise of
a new landmark article in the center of the co-citation network indicate significant
changes in the field. The visualization of such changes in scientific literature may
provide new insights into scientific frontiers.