largely isolated from other journals in the network.
On the other hand, CACM continues to be a source
of information to journals from both the computer
science and IS camps, but is no longer an important
source of information to the professional/managerial
and operations research journal clusters.
Increasing the threshold from 0.10 to 0.15 does not
greatly impact the view of CACM’s relationships to
other journals, although it does lead to a clearer overall delineation of network relationships (see Figure 3).
By combining the information from these three flow
diagrams, we infer that the journals giving the highest
proportion of their overall citations to CACM in 2003
had the following research foci:
• Software engineering, data management, and
computer systems;
• E-commerce;
• Collaboration and group support systems;
• Human-computer interaction;
• IT’s role in society; and
• Emerging areas for IS research and development.
Information flow analysis can also be used to identify
which network journals are the most important sources
of information for CACM itself. Only two journals
(MIS Quarterly and Harvard Business Review) received
more than 10% of CACM’s total citations within the
network in 2003. Other journals receiving at least 4%
of CACM’s network citations include (in descending
order) IEEE Computer, Sloan Management Review,
Management Science, Information Systems Review, and
IEEE Software, all of which are highly respected publications within their respective disciplines.
LEGEND
IS
CS
Mgmt/Prof
OR
Not classified
Figure 3. Information flow (spring embedding, 0.15
threshold).
Information flow analysis also identifies information sources (journals that
receive citations from more journals than
they cite) and information sinks (journals
that make citations to many different
journals, but are not cited by as many in
return). Overall, 52 journals were classified as information sources and 67 as
information sinks. CACM received the
second-highest information-source ranking in the network (net degree of 52,
compared to a net degree of 55 for
Harvard Business Review). Overall, CACM
cited 49 journals in 2003 and was cited
by 101. These scores are obviously highly
sensitive to restrictions on reference lists
or infrequent publication cycles. Some
scores might also be affected by JCR’s practice of truncating most journal-to-journal citation counts less
than two.
Prominence measures. An actor’s prominence in a
social network can be based on either centrality (
visibility due to “extensive involvement in relations”) or
prestige (visibility based on “the extensive relations
directed at them”) [ 4]. In a journal citation network, it
is more appropriate to assess prominence based on
measures of prestige, rather than centrality.
Network actors can exhibit prominence due to having more direct ties with other actors (degree centrality/prestige), shorter path lengths to other actors
(closeness centrality/prestige), or structurally advantageous positions between other actors (betweenness
centrality/prestige) [ 2]. Degree is a localized measure
providing information on an actor’s immediate neighborhood, whereas closeness and betweenness are
global measures.
Prominence measures are best interpreted in light
of the overall level of network centralization. Centralization measures report a network’s degree of centralization as a percentage of that of a perfectly
centralized star network [ 2]. Thus the higher the network centralization, the more closely the network
resembles a perfect star network with one central
actor, indicating unequal distribution of power (or
prestige) within the network. While the centralization
of the IS journal network varies depending on the
measure used, it tends to be moderate at best (ranging
from 21.50% for betweenness measures to 66.45%
for degree measures).
Freeman degree prestige is a common method of
determining journal rankings, including our normal-