Athens.
The final speaker in this session at WebSci '09 is Helen Margetts from the Oxford Internet Institute, whose interest is in what influences people's decision to act collectively (or not). Is it the extent to which others are participating? Related to this is the question of whether use of the Internet makes a difference to such collective action decisions - since it is now possible to know, in real time, how many other people are participating. We can now measure information effects, perhaps for the first time, but what are the appropriate methods for doing so?
Helen's team conducted two experiments to explore these factors, in a laboratory and a (quasi-) field experiment that focussed respectively on existing petitions to the British government on UK and global issues. In each case, participants were given various amounts of information on whether and how many other people had already signed such petitions. Conflicting hypotheses suggested that high numbers of existing signatories could either have a negative effect (free riding effects could set in) or a positive effect (through critical mass or bandwagon effects), while low numbers could similarly have a negative effect (the petition could be seen as a hopeless cause) or a positive effect (signing could make a real difference). Similar hypotheses were also explored for donations rather than mere signatures.
In the event, the study found that very high numbers of existing signatories did encourage further signing, while low numbers produced no clear result. Very high numbers did not necessarily encourage monetary donations, however. The question remains where such critical mass sets in, however (indeed, what exatcly 'critical mass' may mean), and whether perhaps there are multiple tipping points here. Further, it may also be necessary to identify leaders and followers (as people may encounter petitions in real life mainly through friends and family, not in the abstract environment of an experiment), and there may be chain reactions in play which lead to the large-scale adoption of particular causes.
