A 5-point scale is an excellent measure provided you are prepared for everything to come back a 4. Those who use TripAdvisor on a regular basis know the frustration of trying to pick a hotel or restaurant when the best hotels in a given town are a 4 on the TripAdvisor 5-point scale and the worst hotels are also a 4 on a 5-point scale.
(Now of course in reality the best hotel might be a 4.45 and the worst hotel might be a 3.55, and on a 5-point scale there is a big difference between 4.45 and 3.55 … but TripAdvisor does not tell you that, and you are left to stare at a coarse measure and try to make sense of it.
Release 1.0 of Google Consumer Surveys limited DIY Researchers to picking a 5-point scale when researchers wanted to measure something on a scale, and we noted in our very first post about Google Consumer Surveys that the 5-point scale was inadequate to capture subtle gradations.
We are happy to see that Google is beginning to phase out the 5-point scale, in favor of a 7-point scale. Here are 2 examples where research completed in May is being retaken in June with a finer scale.
Look to Google Consumer Surveys (#gsurveys) to eventually move to a 10-point scale. The following (newly spotted) 7-point scale is functionally the same as the 7-point scales above, but graphically, it is subtly different, as Google Consumer Surveys designers begin to make better use of the rectangle they have circumscribed for themselves. In the example below, there is room, horizontally, for another 3 stars, and we would expect to see those additional stars showing up soon, bringing the total to 10 stars on the continuum.
If you are not sure whether to use a 5-point scale, a 7-point scale or a 10-point scale in your DIY research, hire a professional researcher. A professional researcher will be happy to explain the differences to you.