High Quality Content by WIKIPEDIA articles! Historical comparative research is the study of past events and questions using methods in sociology and other social scientific research to inform the possible outcomes and answers to current events and questions. Beginning in the late 1950s, the discipline of history became more linked with sociology. Eventually historical sociology was accepted as a more concrete perspective during the 1970s. Historical investigations are based on the remnants of the past called historical material, which include official documents, diaries and much more as is discussed below. Comparative sociology on the other hand, specifically looks at sociology across regions or nations. Historical comparative sociology differs from historical sociology by focusing on three main issues: causal relationships, processes over time and comparisons.