Communications of the ACM

conference productivity areas—DC and IPCV—are significantly different from the bottom third—MIS, OR, BIO, TH, ML, and DB—whereas the lowest two—MIS and OR—are significantly different from the top third—DC, IPCV, ARCH, COMM, HCI, and SE, information not in Table 3.

If we consider the ratio of journal productivity to total productivity, there are basically two groups: BIO, MIS, and, OR prefer journal publications to conferences, with about 70% of their production published in journals; the differences from all other areas are significant. ML and TH represent an intermediary group that publishes almost half its production in journals; the difference is statistically significant compared to most other areas.

Impact measures. Figure 2 includes the mean and median citations rates (citations per paper per year) for our sample of randomly selected 100 papers (from 2006) from each area (in order of median citations rate); the third column of Table 3 lists the compact letter display of the median citation rates for each area.

MIS citations rates are not significantly different from the next four higher rates—GRAPH, DB, BIO, and HCI—in decreasing order. The two lower-rate areas—ARCH and MM—are significantly different from the third lower-rate area—DC; the other areas are in the same group, with no significant differences among them.

The citation numbers reflect an
interesting relation with productiv-
ity. The higher-productivity areas also
have lower median citation rates. The
correlation is moderately high and sig-
nificant (Spearman rho = −0.63, p-value
= 0.007). We use the Spearman rank
correlation (rho) to detect any mono-
tonic correlation between the vari-
ables, not just linear correlation. The
correlation is even higher for confer-
ence productivity (rho = −0.71, p-value
= 0.001). Thus, on the surface, in areas
like ARCH and MM, researchers write
many papers per year, especially con-
ference papers, but few other research-
ers cite them. One notable aspect of the
high-productivity/low-citation pattern
is that the high-productivity areas tend
to focus on conferences that, given the
usual restrictions on number of pages
in the publications, force authors to
cite only a few relevant papers. How-
ever, a regression of the citation rates
with both total productivity and pro-
portion of journal publication reveals
that only the negative coefficient of the
total production is significant.

table 3. compact letter display of total journal productivity and citations per paper per year; the difference between any two areas is not statistically significant if they have any letter in common.