This study drew on data from two different initiatives in which groups of participants were asked to work together to build knowledge. In the first initiative school students were asked to discuss ethical issues in science, using a moderated online discussion board and in the second, researchers in the field of Technology Enhanced Learning (TEL) used a wiki to develop a vision statement. Despite the different contexts and purposes of the initiatives, the outcomes were remarkably similar in terms of a) the extent and patterns of contributions and b) the quality of the contributions. In both, there was some level of success in that the intended outcome was reached. However, in both, there were fewer contributions than anticipated and the quality of a large proportion of the contributions was disappointing. It is suggested that the reasons for this are related to four factors; the socio-cultural setting, the nature of the knowledge that was being built, the tools used and the way the activity was set up (including setting shared goals). (Contains 1 figure and 4 tables.)