<p> This section is based on surveys from visitors of this website. Questions for these surveys are similar to many similar scientific and government surveys. <p> Each entry in the survey is saved as the number in the range [-2, +2], with -2 having meaning of strongly negative and +2 meaning of strongly positive. <p> We filter surveys to eliminate potential spam, like people entering a large amount of data which are differentiating from the median value. <p> To present survey result, we use the scale [0, 100] for values since it is easier to read for users. <p> To generate a current index (which is always updated) we use data up to 36 months old. We include only cities for which there are at least a certain number of contributors. Our semiannual index is remade twice per year by pushing current index into this historical view.
