Ethnographic maps are visual representations of the ethnic make up of particular regions. Usually multicultural regions which are controlled by an empire.
Here are some examples of ethnographic maps:
Looking through these various maps one notices that each one shows quite different picture to the others. I am aware that such maps often use different criteria to characterise people (eg language, religious affiliation, self identification, or other characteristics). I am also aware that probably all ethnographic maps are biased in some way or favour one particular political/national cause over another.
What I haven't been able to understand though is how data on these maps were actually gathered. Did cartographers go to every single village in a particular area to get their data? or did they visit one or two villages in an area then make a general conclusion about the rest?
I have been to Epirus and have seen how difficult it is to navigate to remote villages even to this day. I'm sure that the rest of the Balkans had villages which are just as hard to get to yet somehow we have ethnographic statistics on them in the mid to late 1800's and before modern highways. So how did cartographers go about creating these?