Chen, C. M., & Paul, R. J. (2001). Visualizing a knowledge domain's intellectual structure. Computer, 34(3), 65-71.

Chen, C. M., & Paul, R. J. (2001). Visualizing a knowledge domain's intellectual structure. Computer, 34(3), 65-71.

vis_paper

本論文進行ACA(author citation analysis)的研究，以IEEE Computer Graphics and Applications上發表論文的作者為分析對象，選擇353位被引用5次以上的作者，利用他們之間的共被引資訊建立網路圖，結果共有28,638條連結線。經過尋徑網路尺度(pathfinder network scaling)的處理，保留下355條比較重要的連結線。為了發現電腦圖學與應用的專長(specialties)，本論文借鏡於White and McCain(1998)的研究，利用PCA(principal component analysis)方法對共被引資料進行因素分析(factor analysis)，結果共得到60個專長，5個較大的專長共可以解釋39%的變異數，而這5個專長分別是Rendering and ray tracing、Computer vision、Geometric modeling and computer-aided design、Volume rendering和Modeling nature。同時也在網路圖上呈現被歸類為這5個專長的作者，來觀察他們在網路圖上的分布情形。

ACA, a special type of citation analysis, focuses on intellectual connections between authors as reflected through the scientific literature. The author co-citation relationship links two authors by how often other authors reference their work together. Author co-citation patterns provide the basis for constructing an alternative view to a knowledge structure.

Pathfinder uses a filtering criterion known as the triangle inequality condition to determine whether to remove or retain each link in the original network. Triangle inequality requires that the length of a path connecting two points in the network should not be longer than the length of other alternative paths connecting the two points, but go through extra intermediate points.

We began by studying author co-citation patterns found in IEEE Computer Graphics and Applications magazine for a period of 18 years. ...  Among them, we entered into the author co-citation analysis only the 353 authors who received more than five citations in CG&A. Although this snapshot derives from a limited viewpoint—the literature of  computer graphics certainly stretches beyond the scope of CG&A— intellectual groupings of these 353 authors provide the basis for visualizing the computer graphics knowledge domain. ... The original author co-citation network contains as many as 28,638 links, which constitutes 46 percent of all possible links, excluding self-citations. Because this many links would clutter visualizations, we applied Pathfinder network scaling to reduce their number to 355.

We enhanced the network by coloring it according to the results generated using principal component analysis (PCA). PCA identified 60 specialties in computer graphics. The largest (rendering and ray tracing) and second-largest (computer vision) accounted for 13 percent and 11 percent of the variance, respectively. The five largest specialties accounted for 39 percent of the variance. Remaining specialties are relatively small.

Factor 1: Rendering and ray tracing.
Factor 2: Computer vision.
Factor 3: Geometric modeling and computer-aided design.
Factor 4: Volume rendering.
Factor 5: Modeling nature.

The knowledge landscape visualizes intellectual structures. A virtual landscape like this provides an intuitive gateway for users to access the scientific literature. Researchers new to a field can gain a useful overview by using the knowledge landscape to establish their own mental model of the field and track the development of their own domain.