Comparative politics is one of five sub-fields in political science, along with American politics, political theory, international relations and political economy. Comparative politics researchers use many techniques -- from statistics to anthropological field work -- that fall under the rubric of comparative method. What unites the techniques is comparison involving a few political entities, such as countries, states, provinces or even cities. This is distinctive from what international relations specialists do, which involves testing hypotheses about large groups of countries, like democracies or all poor countries.

Studying a Few Cases

The comparative method aims to identify specific political trends by isolating data to test hypotheses involving just a few cases. For example, a comparative scholar may study the frequency of intrastate warfare among two, three or four states in Central Africa where natural resources like diamonds are looted. The goal would be to begin figuring out whether the unregulated and chaotic trade in precious natural resources is a cause of civil wars in Central Africa.

Area Studies

The comparative method almost uniformly requires focus on a single region like Central Africa, Southeast Asia or Western Europe. The goal is to locate commonalities between cases that have geographical, historical or cultural similarities. In practice, this often means the researcher takes a regional approach. For example, a comparativist might study the strength of government institutions, the role of non-governmental organizations or the growth of civil society in Africa's former Belgian colonial holdings -- now known as the Democratic Republic of Congo, Rwanda and Burundi.

Qualitative Comparative Research

Most comparative research projects in political science deploy either qualitative or quantitative methods to test hypotheses. Using methods common in cultural anthropology, qualitative researchers learn as much specific information as possible with a goal of producing detailed, nuanced information that cannot be represented by statistical analysis. This can mean long-term field research in case countries. The key is that the researcher spends time learning to understand the society by becoming acquainted with language and culture -- and learning historical context. Long open-ended interviews and/or surveys are common.

Quantitative Comparative Research

Quantitative methodology means statistical analysis involving hard numbers. It values parsimony over nuance. If often isolates one possible cause of a phenomenon -- say, civil war in Africa -- such as rising food prices. Statistical software traces the rate of new intrastate conflict against the rate of food price increases. If the test results suggest a strong positive correlation between food price hikes and the onset of civil war in Africa, the researcher must then explain why she thinks this could suggest a causal rather than merely correlative relationship.