Communications of the ACM

ed in university CS departments; for BIO, some non-CS faculty were hosted in biology-related departments, for MIS, in business and marketing departments, and for OR in applied math and engineering departments. However, surprisingly, this pattern also holds for IPCV researchers, with about one-third affiliated with radiology and medical departments. The quantity of researchers in those areas not in CS departments may indicate those areas are more “interdisciplinary.” 13

The number of students in the
sample may indicate, in a first ap-
proximation, the number of students
working in each area. That number
divided by the number of CS faculty in
the sample may likewise be an indica-
tor of the availability of students per CS
researcher. Thus, MM and ARCH had
the most students per CS researcher,
while MIS, DC, and TH had the fewest
students per CS researcher.

table 2. characteristics of the samples and the population in each area: stud. is number of students: non-cs is number of non-cs faculty; cs is number of cs faculty in the sample; Resea. is total number of researchers; and Papers is total number of papers (published from 2006 to 2010) according to DBlP computer science Bibliography.

area AI ArCH BIO C+PL COMM DB DC grAPH HCI IPCv MIs ML MM Or se seC TH

stud. 6 10 4 4 4 8 3 5 8 4 0 4 9 2 4 4 3

sample non-cs cs 0 24 3 17 11 15 0 26 0 26 0 23 0 27 3 23 3 19 12 12 19 11 5 11 0 11 19 9 2 24 0 26 4 23

Resea.

2244

3662

8406

1001

4395

1716

1112

2176

3229

6826

1175

2619

3623

3103

2278

1527

1595

Population
Papers
4461
6666
8037
1244
6640
3066
1097
2913
5696
10959
1800
3728
4790
6051
4993
2690
5534

figure 1. Production per year (in order of total productivity); the percent in each bar is the proportion of journal productivity to overall productivity.

conference Journal

8

6

publications/year

4

2

20% 21% 22%

28% 26%

26% 33%

45%

26%

17% 19%

31%

24%

48%

70%

76% 69%

0

mIS or th Db c+Pl aIgraPh Sec ml bIo mm hcI Se arch IPcV Dc comm

dered by total productivity (the sum of conference and journal productivity).

Table 3 lists the significant differences in total and journal productivity as a “compact letter display,” a visualization tool showing nonsignificant differences between two areas; that is, the difference between the average total productivity of two areas is not statistically significant if the areas share a letter in common. When comparing any two areas, two or more letters in common means the same as one letter in common; that is, the areas are not significantly different. Only when two areas have no letters in common is the difference between them statistically significant. Each letter is an indicator of a maximal subset of areas in which differences are not statistically significant; for example, total production of DC (“d”) is significantly different from that of DB (“ab”), since they have no common letter. However, DC (“d”) is not significantly different from COMM (“cd”) because they have the letter “d” in common. The second column lists the nonsignificant differences for journal productivity; for example, the OR in the journal productivity column includes all four letters (“abcd”), meaning OR is not significantly different from any other area, because OR has at least one letter in common with each other area.

Regarding total productivity, although the data seems to show three groups—higher productivity (ARCH, COMM, DC, and IPCV); middle; and lower productivity (MIS and OR)— almost all differences are not significant at 95% confidence level, as in Table 3. The only significant differences are, in general, between MIS and OR and the higher-productivity group. There are also significant differences between DB and TH and some of the higher-productivity areas but not all. Thus, one cannot claim that in general there are total productivity differences among the CS areas except for a few cases covered earlier.

For journals, BIO has significantly higher productivity ( 3. 44 papers per year) than all other areas, except the next four higher—COMM, MIS, ML, and OR; COMM is significantly different from the lower journal productivity areas—AI, C+PL, and DB—as in Table 3.