Policy and Complex Systems
an explanatory and predictive model about why and how scientific knowledge ( with publication as a proxy for knowledge ) is created , diffused , and accumulated , making no other assumptions about quality .
Modeling
System dynamics enables an approach to modeling structures and simulating behaviors in cases where a structure or complex phenomena emerges . We constructed a theoretical , testable model of creation , diffusion , and accumulation and obsolescence of scientific knowledge . The system 6 can be modeled as the relationship between stock and flow . Stock is conceptualized as accumulation of knowledge , which increases ( or decreases ) over time . The magnitude of stock is influenced by flow ( inflow or outflow ) over time . Relationships of such stock and flow are visualized within system dynamics as shown in Figure 4 .
The stock and flow model includes the following :
���������������������������������������� variables in the structure of system . ���������������������������������������termined by the inflow and outflow process . �� ��� ������� ��� ���������� ��� �������� auxiliary variables such as initial quantity , creation rate , and obsolescence rate of the stock of scientific knowledge . �� ���� ���������� ���������� ��� ��������� by drawing upon existing scientific knowledge ( which can be different or similar knowledge ). �� ����������� ���������� ���������� ��� stored and adds to and replaces some scientific knowledge . ���������������������������������������combination of existing scientific knowledge and the creation rate . �������������������������������������cence rate ( or death rate ). ������������������������������������������� scientific knowledge and its average life .
This scientific knowledge growth model is very similar to population growth models based on births , living persons , and deaths , which is a traditional system dynamics model . The population is the agglomeration of the number of births as inflow , the current stock of people , and the number of deaths as outflow , just as scientific knowledge consists of all the new information , accepted scientific theory along with active research , minus the scientific knowledge that no longer remains actively used or exchanged . ( One key difference in the knowledge model is that some ‘ obsolete ’ knowledge could be revived to contribute to the system , which have been discussed in the literature as ‘ sleeping beauties ’ ( Van Raan 2004 ) but might also be called ‘ zombies .’) Scientific knowledge is normalized over time : some of the normalized scientific knowledge becomes generalized ; and some of it disappears . In these respects , we can assume that scientific knowledge repeats this process over time with an accumulation . Based on basic assumptions , a stockflow system model of scientific knowledge growth is constructed as seen in Figure 4 .
6
A system is a set of entities ( called the elements of the system ) mutually related in such a way that the state of each element determines and / or is determined by the state of some other element or elements , and every element is connected by the state of some other element or elements , and every element is connected to every other by a chain of such elements . A system as a whole has a function only if it is an element in a more inclusive system , that is , only if it affects something other than itself . ( Self-perpetuation does not count as a function in this sense .)
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