In many cases, a 5-star rating system where most of the ratings are either 3 or 4 is actually no better then just a thumbs-up/thumbs-down rating system.
However, given that 5-point scales are probably here to stay, we are forced to make the best use of them we can.
I've seen this attempted over and over on the net with the same results every time: Each episode of a show is 4-stars /- .5 stars.
This goes all the way back to the Babylon-5 website, probably the first source for this kind of data.'s first season, is considered an entirely atrocious episode by even the fans.
Yet it has a 6.1 of 10 "Fair" rating on ) Thus even when a bimodal distribution is not a problem, on a 5-point scale the upward bias often results in only 2 or 3 meaningful data points.
This is problematic because it minimizes differentiation.
In other words the distribution of ratings tends to cluster around two different numbers (e.g., 1 and 5) rather than offering a normal distribution where the ratings cluster around a single height (e.g., 3).If you use i Tunes with an i Pod, you can change the rating of a song on your i Pod and the change will be reflected in your i Tunes database the next time you sync your i Pod.The "Shuffle Songs" feature available on more modern i Pods has an option to have songs with higher ratings be played more often.On RPGnet, for example, we discovered that 90% of this 5-point rating system was 3 or higher with an average around 4.Randy Farmer of Yahoo suggests that this scale limitation is particularly troublesome for fan-based ratings, such as those found on episodic TV sites: Only the fans of a show evaluate the episodes, and being fans, will never rate an episode one or two stars, ever.