by Open Knowledge Team on May 11, 2010
Problem 1: Reputation Involves Costs and Needs Rewards
The eBay reputation system proves that if buyers are uncertain about seller’s trustworthiness, they will reward better seller reputations by raising their offers. Another aspect we must consider is that if it is costly to maintain a reputation for high quality (at least in time and effort), then a good reputation needs to be rewarded by the cost of building one. Similarly a bad reputation or a decline in reputation should incur a loss that exceeds the benefit from opportunistic behavior [7].
Reputation systems motivate people in ways monetary economies do. Any community that is equipped with a reputation system can truly benefit of a raise in its value only if the associated business model is capable to redistribute part of the extra value to the most valuable members of the community and the system provider.
Problem2: Avoiding Transferability of Reputation
In some rating based reputation systems it is to most raters’ perceived advantage that everyone agree with the rater. This is how chain letters, Amway and Ponzi schemes work [12,13]. They establish a system in which customers are motivated to recruit other customers.
As an example: If a vendor offered to discount past purchases if enough future customers buy the same product, it would be hard to get honest ratings for that vendor. All the buyers, in order to foster new selling and get the discount would rate the vendor very high.
Problem3: Verifying Assertions and Preventing Shilling
Among the simpler attacks that a reputation system can suffer the simplest yet very spread and dangerous, is called shilling. This term is often used to refer to submitting fake bids in an auction, but it can be considered in a broader context of submitting fake or misleading ratings, often exploiting identity forgery.
In particular, a person might submit positive ratings for one of her friends (positive shilling) or negative ratings for her competition (negative shilling). Either of these ideas introduces more subtle attacks, such as negatively rating a friend or positively rating a competitor to trick others into believing that competitors are trying to cheat.
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by Open Knowledge Team on May 9, 2010
“How reputation evaluation can help WEB2.0, Enterprise2.0 and other type of Cooperative Digital Communities to improve User Generated Contents quality, foster participation and community growth, putting in practice business models that use reputation as a community digital currency.”
Cristian Brotto
Ph.D. Candidate – Università Degli studi dell’Insubria (Varese),
Software Engineer and Business Intelligence Consultant.
Email: cristian.brotto@gmail.com
Linkedin: http://it.linkedin.com/in/cristianbrotto
Twitter: http://twitter.com/cristianbrotto
Sito: www.webbrainys.com:3000
Many among the largest WEB2.0 communities are built upon the concept of Users Generated Contents (UGC), a business model in which the members of the community are also the creators of the contents/resources the community rely on. Notable examples of this kind are the cooperative encyclopedia Wikipedia.org and the video-sharing service YouTube.com.
This type of systems sometimes provides means to cooperatively evaluate and classify the resources the users share, but the vast majority of them lack an accurate ranking system for their most proficient members and none of them includes effective rewarding mechanisms.
Although rough, the current technology seems to be sufficient to confer to some cooperative web communities a good success, which for the most part appears to be due to their core-members passion and commitment. Nevertheless, deficiencies like the ones described usually involve that over time only a small amount of the members keep committed and willing to produce resources of a certain quality. This tendency leads to the situation in which, although the community grows in terms of numbers, in proportion its value decreases.
Providing cooperative communities with effective rewarding systems could solve the problem. Unfortunately this approach rarely and loosely has been implemented so far. The reason is that the task involves several not trivial side problems. The biggest is the necessity of an advanced ranking mechanism to evaluate the members of the community. Such a method should consider complex factors like competence and commitment, but at the same time it should be easily understandable and shared by the members of the community. Also, in order to make sure that the members agree with the rating system it must involve their collaboration, which implies finding ways to prevent misuse.
This is not an easy task, nonetheless considering the fast diffusion of web2.0 communities and the new emerging Enterprise2.0 communities the problem is no longer to be underestimated.
Digital communities should start thinking of new means to rise their quality standards in order to keep effective and successful over time.
One solution to the problem could be the adoption of an RCE business model (Reputation Community Evaluation). The RCE model exploits users reputation, rather than only competence and/or commitment, as evaluation parameter, and implements ways to use reputation as a digital currency in order to promote an healthy community growth.
The assumption is that communities equipped with a reputation system can benefit of a raise in their value. Using an RCE business model this rise in value can be then capitalized and redistributed among its most proficient members and the system provider.
To truly understand the real value of reputation we need to set our minds to think of reputation as a monetary capital, as a matter of fact although by personal experience we all have an idea of what reputation means, this idea is often partial and doesn’t cover all the complexity and potential that reputation involves.
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