Kaarle Krohn's Folklore Methodology was the first systematic attempt to state a method of studying folkloristic materials. For centuries scholars had collected folkloristic texts and had commented on them, but they had not tried to formulate a method of investigating folklore.

Folklore Methodology became the handbook for the great Finnish School of folklore research. It provided for its students a guide to the geographical research of traditional materials, a radical departure from the literary scholarship that had dominated folklore studies.

Krohn's book explores the causes and modes of folklore diffusion, development, and destruction; it outlines the influences that cause change in folklore; it provides valuable insights into the nature of folklore; and, finally, it develops geographic methods for analyzing, classifying, and reconstructing individual items from the folk repertoire.

While many developments have taken place since Krohn first published his guide, important new concepts of folklore research sprang from his efforts. For this reason, Folklore Methodology is mandatory reading for every serious student of folklore.