CiteSpace by a single threshold control time partition number of network nodes, to meet the threshold condition was only citation visualized with Top N , The TopN% , ThresholdInterpolation, SelectCiters total . 4 model setting mode.
(1) Top N selects the N most cited citations;
(2) TopN% is sorted by the number of citations first and then the citations are selected by percentage (N% ). The thresholds of each time partition in these two methods are exactly the same.
(3) Threshold Interpolation (threshold Interpolation ) sets the threshold from three levels of the cited frequency c ( citation ), the co-cited frequency cc ( cocitation ) and the co-citation coefficient ccv ( cosinecoefficient ) of the two literatures , where the formula for ccv is wherein CC (i, j) is the documents i and document j co-citations, C (i) and C (j) is the number of times each cited, for example, at a time partition, documents i and j literature co cited 2 times Document i cited 4 times Document j cited 3 times, the CCV = 2 / sqrt (4 × 3) ≈ 0.577 . It sets threshold anchor points in the first, middle, and last time partitions of the entire time span respectively, and the thresholds of the remaining time partitions are calculated using a linear interpolation algorithm to achieve the personality of different time partition threshold
Change.
(4) Select Citers . Select Citers according to the TC field value in the citation record , and then use Top N , TopN% ,
One of the methods in ThresholdInterpolation is used as a threshold for screening references in cited literature.
Threshold tuning can be
adjusted
according to the number of selected citations, nodes, and connections in the data processing report
(Space Status
and
Process Reports
) in the
lower left corner of the Citespace software interface . To determine a reasonable threshold, repeated trial calculations and comparisons are required. The value corresponding to the space column in the Space Status
text box
on the left side of the software interface is the number of valid references for the citations in the time zone. Missing bibliographic fields and duplicate references are not counted. Nodes refers to the number of references that meet the threshold conditions. The value of Records within the chosen range in Process Reports refers to the number of valid citations, and citations that lack references are not counted.
