[1][2] Concerned with collecting data about the history of wars and conflict among states, the project has driven forward quantitative research into the causes of warfare.
The Correlates of War project seeks to facilitate the collection, dissemination, and use of accurate and reliable quantitative data in international relations.
The most widely used databases developed by the project include an identification of independent states since 1816, a list of interstate and civil wars since 1816, a list of "militarized disputes" (militarized crises that end short of war), and national capabilities measured annually for all countries since 1816 (including the size of countries' military, their energy consumption as a proxy for industrialization, population size, urbanized population, and raw material production of iron and steel).
In addition to generating these several data sets and constructing quantitative indicators of key variables that might turn out to be correlates of war, the project has completed and published a variety of statistical analyses and hypotheses.
Singer's group used a three-digit identification code for states (per the system since the Congress of Vienna) in their dataset correlated loosely with geography.