When you make a survey surveyor might write the data incorrectly mistakenly, it happens. If the data is written down mistakenly the basic statistics like median

When you make a survey surveyor might write the data incorrectly mistakenly, it happens. If the data is written down mistakenly the basic statistics like median, mean, standard deviation etc won't change much. After all it is just a survey and you already sample from the population. So, even if the data in the sample was correct you will not get the exact population data. But of course if inconsistency in the data is found it is further analyzed whether if it was a small mistake intentional wrong doing.