Expectation phenomenon

In most cases reading and interpreting a visualization is a straightforward exercise. But in some cases that is not true. Very quickly the analyst encounters what can be called the “expectation phenomenon.”

In order to explain the expectation phenomenon, consider Fig 6.5 which shows a visualization of customer sentiment. The legend says that negative comments are in red and positive comments are in green.

It appears that there are many more negative comments than positive. But there is a rational explanation for this. Suppose you go into a restaurant with your family to have a meal. You have a wonderful meal and you leave the restaurant happy and satisfied. When that is your experience, do you provide any feedback? Usually not. You went into the restaurant expecting to have a good experience and the restaurant met your expectations.

Now suppose you go into a restaurant and you have a bad experience. The food was bad. Or the waitress...