# An Extended Framework for Recovering From Trust Breakdowns in Online Community Settings
## 4 Experiments and Results
### Experiment 2: Comparison of Dynamic E-Marketplaces  
The purpose of this experiment is to investigate the efficiency of the proposed framework by evaluating the average reputation values, total market transactions, market transactions at different  
Figure 3: (**a**) Number of untrustworthy service providers; (**b**) Utility obtained at different time points. Figure 2: (**a**) Average reputation values; (**b**) Transaction volumes at different time periods. time points, number of untrustworthy service providers and number of utilities obtained at different time points in different dynamic e-marketplaces. Initially, the e-marketplaces have the same number of trustworthy service providers as in Experiment 1 (i.e., 50). However, in this experiment we allow new service providers to join the e-marketplace at the end of each time period. The number of newly joined service providers is equal to the number of untrustworthy service providers leaving the e-marketplace in each time period. As a consequence, the number of trustworthy service providers remains constant over the course of the experiment. For simplicity, the results of each sub-experiment are analysed after 1500 time periods. In the first sub-experiment, we compare the average reputation values of service providers in different e-marketplaces. As shown in Figure 4, the average reputation values of service providers in the e-marketplace incorporating our framework are slightly higher than in ALLD and ALLC. Note that when compared with Griffiths, the result is almost equivalent to our framework. However, all e-marketplaces maintain the same high average reputation values throughout the entire experiment. It is also worth noting that implementing different reputation approaches clearly results in a different outcomes. In the second sub-experiment, total transactions and transaction volumes at different time periods are measured. In Figure 5a, ALLC has the highest total number of transactions compared to other e-marketplaces as a result of an optimistic setting. Interestingly, the total transaction volumes of Griffiths increase sharply, then remain nearly constant after time period of 720 as the ability for switching to other trustworthy service providers makes the majority of them run out of products. The increase rate of the total number of transactions of the e-marketplace incorporating our framework is greater than for ALLD and Griffiths (after a time period of 1050). In Figure 5b, the comparison of transaction volumes generated by different e-marketplaces at different time periods are presented. Again, we notice a sudden drop of number of transaction volumes generated in Griffiths which is similar to the results in Figure 2b. However, the reason of this drop-off is not due to the lack of trustworthy service providers, but rather the lack of available products provided by trustworthy service providers. Conversely, the decreasing number of market transactions in ALLD, ALLC and the e-marketplace incorporating our framework is mainly due to the increasing number of untrustworthy service providers. Clearly, for an e-marketplace with limited inventory, our framework is capable of dealing with a constant number of defective service providers, helping the e-marketplace to operate and generate market transactions better than other approaches. Figure 4: Average reputation of each e-marketplace. In the third sub-experiment, the numbers of untrustworthy service providers in different e-marketplaces are compared. As we can see in Figure 5(a), the e-marketplace incorporating our framework and ALLC have the lowest number of untrustworthy service providers as these e-marketplaces are driven by the benefits of the forgiveness mechanism. Interestingly, the number of untrustworthy service providers in Griffiths outnumbers the number of untrustworthy service providers in all other e-marketplaces by a huge margin due to the capability of product consumption.