[waivek]

How can app reviews be used to draw conclusions of how users feel about the app if less than ten percent of the users write app reviews?

It's like surveying a small percentage of an electorate by asking them who they'll vote for for and deciding the result based on the survey.

[hungerstrike]

Actually, 10% of a population is a damn good sample size for just about any scientific or medical study. It’s quite large to be honest.

Anyway, once again... where is your evidence that this rarely happens?

[waivek]

It's a biased sample because people who are fine with their app don't write reviews. The sample is polluted.

My evidence can drawn from the fact that ten percent of people write reviews. A fraction of that are negative. If an occurrence happens say five out of a hundred times,that's a rare occurrence.