Journal of Information Science

When statistics and data are taken, the science of the statistics is called

demography. However demography is also referred to in a broader sense

encompassing a few other closely related datas taken connected by a few subjects

such as sociology, anthropology, economics, geography, planning and development,

biology, and medicine and public health. The connection is called interdisciplinary

demography. This intellectual demographic structure is analyzed based on 65 journals.

The authors have come up with 12 clusters of subject specialties. As a

discipline, demography merges with other fields, with uncertainty in its boundaries. The

understanding of the boundaries require an understanding of the detailed structural

information in its large context, therefore one needs to explore the intellectual structure

of demography by revealing connections with its subject specialties and outside them.

Citation analysis is commonly used to explore the intellectual structure of a given

discipline. The internal and external scholarly communication of a discipline can be

understood by mapping its published literature. The principal methods to map the

structure of a discipline are co-word analysis, bibliographic coupling, co-citation

analysis, and intercitation analysis. this paper aims to map the structure of demography-

related journals using intercitation data in a valued directed network.

Mapping such an intellectual structure is particularly valuable in terms of

delimiting the boundaries of the discipline in its large context and presenting the visual

and quantitative understanding of the interactions between representative demography-

related journals.

The authors addressed the following three questions when collecting the

intercitation data from 65 demography-related report JCR (Journal Citation Report):

1. What is the overall intellectual structure of demography-related journals in its

large context?

2. To what extent are all selected journals related to the demography journals in

terms of citation percentages?

3. Have the demographic citation patterns changed over time?

Statistical procedures:

To determine the subject specialties of the 65 demography-related journals, the

authors performed a cluster analysis on the standardized matrix of both rows and

columns. The standardized matrix was subjected to complete linkage hierarchical

clustering. Complete linkage clustering requires that ‘any candidate for inclusion into an

existing cluster must have certain level of similarity to all members of that cluster.’

Therefore, it tends to produce compact and distinct clusters of highly similar cases. To

visualize the network connections, they created a network diagram using the same

standardized matrix. The threshold of the journal citations was set to optimize the

subject relatedness of these journals. They further demonstrated how demographic

information travels within and across its boundaries by calculating the citation

percentages of all the selected journals in relation to the demography ones. Finally, the

authors tested whether there was any significant change in citation patterns among the

selected journals over time. For that purpose, the raw data of the yearly matrices were

correlated with those of the aggregated matrix using Quadratic Assignment Procedure

(QAP). A similar procedure was applied to the data among the yearly matrices. The

program Ucinet 6 for Windows was used for the cluster analysis and network diagram in

this study.

Overall intellectual structure of the 65

Demography-related journals

Figure 1 presents the result of the hierarchical clustering of the 65 demography-related

journals for their subject relatedness. The selected journal titles and their abbreviations

are listed in the notes to the diagram. A 12-cluster solution is chosen identifying 12

groups of journals. Cluster 1 is composed of sexual health journals and an adolescent

health journal (A, AC, JAH,PSRH, STD). Anthropology journals and human biology

journals are grouped to form cluster 2 (AA, AJPA, ARA, AHB, AJHB, CA, HB). Cluster 3

comprises economics journals and a human resources journal (AER, JEL, JHR, JLE,

JPE, JPEc, JPuE). Cluster 4 consists of public health journals, including those on

epidemiology, social sciences and health, and health policy (AJE, AJPH, BWHO, HPP,

IJE, JECH, JHSB, MQ, SSM). Contraception and human reproduction journals

joingynecology and obstetrics journals in cluster 5 (AJOG, C, HR, IJGO, OG). Cluster 6

embraces sociology and social science journals (AJS, ARS, ASR, ESR, SF, SSR).

General and comprehensive demography journals are grouped in cluster 7 (D, PB,

PDR, PRPR, PS). Cluster 8 includes development journals plus a human geography

journal (DC, EDCC, JDS, PHG, WD). The two human migration journals are clustered

with a race and ethnicity journal in cluster 9 (ERS, IM, IMR). The European-based

demography journals are joined in cluster 10 by family history and population

environment journals (EJP, JFH, P, PE). Journals of family studies and aging are

grouped in cluster 11 (G, JCFS, JFI, JMF, RA). Finally, four family planning and social

biology journals are included in cluster 12 (IFPP, JBS,

SB, SFP). It is of interest to note that the 16 demography journals are split into different

subject specialties:

– general and comprehensive, European-based general and comprehensive, family

planning and social biology, and human migration, with PSRH joining the sexual health

cluster and JPE the economics cluster. It is also important to see the subject

relatedness in the combinations of journals in these clusters, such as the anthropology

and human biology journals, the aging and family studies journals, and the family

planning and social biology journals.