by Christopher Allen & Shannon Appelcline [This is the fourth in a series of articles on collective choice, co-written by my collegue Shannon Appelcline. It will be jointly posted in Shannon's Trials, Triumphs & Trivialities online games column at Skotos.] Last year in Collective Choice: Rating Systems we took a careful look at eBay and other websites that collect ratings, and used those systems as examples to highlight a number of theories about how to make rating systems more useful.

My colleague, Shannon Appelcline, has been working on a game rating system for RPGnet. This has resulted in real-world application of the principles for designing rating systems which we've previously discussed in our Collective Choice articles. Shannon's newest article, Ratings, Who Do You Trust? offers a look at weighting ratings based on reliability. On the RPGnet Gaming Index we've put this all together to form a tree of weighted ratings that answer the question, who do you trust?

In Collective Choice: Rating Systems I discuss ratings scales of various sorts, from eBay's 3-point scale to RPGnet's double 5-point scale, and BoardGame Geek's 10-point scale. Of the various ratings scales, 5-point scales are probably the most common on the Internet. You can find them not just in my own RPGnet, but also on Amazon, Netflix, and iTunes, as well as many other sites and services. Unfortunately 5-point rating scales also face many challenges in their use, and different studies suggest different flaws with this particular methodology.