I see it all too often in history books today: interviews, diaries, or otherwise "anecdotal" pieces of evidence are used to back up claims about trends. Interviews with three farmers, for instance, might be used to claim that farmers on the whole were receptive of new production technologies. Surely not all historians argue like that, but the pervasiveness of these claim-making practices, often found in social history and some making heavy use of ethnographic methods, is astonishing to me.

To put the question another way, what use are "micro" pieces of evidence other than saying "At this point of time, somebody thought or did a certain thing, so we know for sure people did not all think or behave in the same way"? How have historians tried to justify their choice of evidence?