
What do Amazon's product reviews, eBay's feedback score system, Slashdot's Karma System, and Xbox Live's Achievements have in common? They're all examples of successful reputation systems that enable consumer websites to manage and present user contributions most effectively. This book shows you how to design and develop reputation systems for your own sites or web applications, written by experts who have designed web communities for Yahoo! and other prominent sites. Building Web Reputation Systems helps you ask the hard questions about these underlying mechanisms, and why they're critical for any organization that draws from or depends on user-generated content. It's a must-have for system architects, product managers, community support staff, and UI designers. Scale your reputation system to handle an overwhelming inflow of user contributions Determine the quality of contributions, and learn why some are more useful than others Become familiar with different models that encourage first-class contributions Discover tricks of moderation and how to stamp out the worst contributions quickly and efficiently Engage contributors and reward them in a way that gets them to return Examine a case study based on actual reputation deployments at industry-leading social sites, including Yahoo!, Flickr, and eBay
There's a blog, book, and wiki.
Some keyword searches: http://www.worldcat.org/search?q=kw%3A+online+reputation+sys...
https://scholar.google.com/scholar?q=online%20reputation%20s...
Book: http://shop.oreilly.com/product/9780596159801.do
Wiki: http://buildingreputation.com/doku.php
Blog: http://buildingreputation.com/
I can pretty much guarantee there are elements of this you're not considering which are addressed there (though there are also elements which Farmer and Glass don't hit either). But it's an excellent foundation.
Second: If you're going to have a quality classification system, you need to determine what you are ranking for. As the Cheshire Cat said, if you don't know where you're going, it doesn't much matter how you get there. Rating for popularity, sales revenue maximization, quality or truth, optimal experience, ideological purity, etc., are all different.
Beyond that I've compiled some thoughts of my own from 20+ years of using (and occasionally building) reputation systems myself:
"Content rating, moderation, and ranking systems: some non-brief thoughts" http://redd.it/28jfk4
⚫ Long version: Moderation, Quality Assessment, & Reporting are Hard
⚫ Simple vote counts or sums are largely meaningless.
⚫ Indicating levels of agreement / disagreement can be useful.
⚫ Likert scale moderation can be useful.
⚫ There's a single-metric rating that combines many of these fairly well -- yes, Evan Miller's lower-bound Wilcox score.
⚫ Rating for "popularity" vs. "truth" is very, very different.
⚫ Reporting independent statistics for popularity (n), rating (mean), and variance or controversiality (standard deviation) is more informative than a single statistic.
⚫ Indirect quality measures also matter. I should add: a LOT.
⚫ There almost certainly isn't a single "best" ranking. Fuzzing scores with randomness can help.
⚫ Not all rating actions are equally valuable. Not everyone's ratings carry the same weight.
⚫ There are things which don't work well.
⚫ Showing scores and score components can be counterproductive and leads to various perverse incentives.
I'm also increasing leaning toward a multi-part system, one which rates:
1. Overall favorability.
2. Any flaggable aspects. Ultimately, "ToS" is probably the best bucket, comprising spam, harassment, illegal activity, NSFW/NSFL content (or improperly labeled same), etc.
3. A truth or validity rating. Likeley rolled up in #2. But worth mentioning separately.
4. Long-term author reputation.
There's also the general problem associated with Gresham's Law, which I'm increasingly convinced is a general and quite serious challenge to market-based and popularity-based systems. Assessment of complex products, including especialy information products, is difficult, which is to say, expensive.
I'm increasingly in favour of presenting newer / unrated content to subsets of the total audience, and increasing its reach as positive approval rolls in. This seems like a behavior HN's "New" page could benefit from. Decrease the exposure for any one rater, but spread ratings over more submissions, for longer.
And there are other problems. Limiting individuals to a single vote (or negating the negative effects of vote gaming) is key. Watching the watchmen. Regression toward mean intelligence / content. The "evaporative cooling" effect (http://blog.bumblebeelabs.com/social-software-sundays-2-the-...).
Despite being written more than two decades ago, most of the conclusions from Lessons.. are still fresh and applicable to game mechanics today.
Randall (@frandallfarmer) is also the author of Building Web Reputation Systems, published by O'Reilly - http://www.oreillynet.com/pub/au/3900. Another nice reading, if you're interested in the subject.
Definitely worth looking at.