Question

What is an example when sampling is done wrong and predicted an incorrect outcome? Were there biases in the initial survey? What could have been done differently?

Answer 1

A sample "N" number of days is taken for average rainfall in UAE over the year for each month, which can be  the average rainfall for the whole world as UAE.

This prediction is not applied for the whole world because the geographical locations and conditions would vary for different countries and would more likely to fit for middle east region.

The Sampling is more likely to be biased because that for particular location and it may or may not be apllicalible to nearby countries not for all . it could be used for Gulf countries not for all.

If We want to actually measure the average rain fall then we can take the sample from each countries for a longer duration and then after processing we can conclude about average rain fall.