As Figure 2 shows, we found evidence for critical thinking in both
face-to-face seminars and computer conferences. The depth of critical thinking
ratios were more positive in computer conferences for all seminar groups. This
difference is significant at 4% as measured in a matched sample difference test
(t = 4.58 > critical value of 4.3). The highest difference was found in
group C's transcripts, which would be interesting, if significant, since that
was the largest seminar group. However, an analysis of variance with group and
technology as the factors showed no significant difference between groups
(Table 2).

Figure 2.
Critical thinking is deeper in computer conferences.
Table 2. ANOVA of overall depth of CT ratio, by group and technology.
| Source of Variation | SS | df | MS | F | P-value | F crit |
| Groups | 0.00 | 2.00 | 0.00 | 0.3 | 0.773 | 19.0 |
| Technologies | 0.08 | 1.00 | 0.08 | 20.9 | 0.045 | 18.5 |
| Error | 0.01 | 2.00 | 0.00 | | | |
This increase in depth of critical thinking took place against a background of
reduced participation. We found 18 times more markable statements per week in
the seminar transcripts than in the computer conferences. Perhaps they found
writing in a computer conference to be less spontaneous and take more thought
and time than making a comment in a seminar. To explore this, and other
questions, we need to look in more detail at the different elements of critical
thinking.