I recently worked on a project where I had to map out 70 location sites in a city.
The latitude and longitude were given to me by the client.
When I first mapped out the locations, I assumed the coordinates were correct since they all fell within the city.
However, I decided to check the latitude and longitude of each location and compare it with street view in Google Maps. I noticed that most of the longitude and latitude were incorrect. They fell within the city but in incorrect locations within the city (I also had corresponding description of each location and pictures and they did not match with what I was seeing in Google Maps)
Now, I had no problem checking each site in Google Maps since there were only 70 locations.
But I was wondering... What if I had hundreds of hundreds of locations to work with? How would I be able to check if coordinates are correct (obviously if the coordinates show me a different part of the world it would be obvious, but what if it is like my situation above where they look like they are in the right place and SEEM correct?). Is it my responsibility as a GIS person to figure this out if the client gives me incorrect data?