murders. Bergmann writes that "researchers frequently fail to distinguish between pogrom and massacre" and "the differences lie in the fact that massacres are conducted by more highly organized and better armed assailants (often military or police units)... whereas the elements typical to a pogrom [are] a large group of attackers acting on a short-term basis within a local framework, and the destruction and looting of property" Related terminology Usage of the word pogrom overlaps with other terminology used to describe collective violence. Partial synonyms include: Ethnic riot: An ethnic riot is a riot focused on the persecution of an ethnic group. Donald L. Horowitz wrote in 2001 that "the pogrom is not so much a complementary species of interethnic violence as it is a subcategory of the ethnic riot". Prior to his death in 2007, scholar John Klier began preparing an article entitled "Were the Russian Pogroms a 'Deadly Ethnic RIot'?", referring to the term developed by Horowitz. In their 2002 book Exclusionary Violence: Antisemitic Riots in Modern German History, Christhard Hoffmann and Werner Bergmann use the term exclusionary ethnic riot or exclusionary riot as a synonym for pogrom. Genocidal massacre: A genocidal massacre is the killing of a local group within an ethnic minority, described by Leo Kuper as "the annihilation of a section of a group — men, women and children, as for example in wiping out of whole villages". George Andreopoulos wrote that "With [the] category [of genocidal massacres] we are now equipped to describe many pogroms, mass executions, and mass murders", referring to the term originally proposed by Kuper in 1982. William Schabas wrote that "Examples [of genocidal massacres] would be pogroms and mass executions. In a discussion of Balkan Genocides, Paul Mojzes wrote that "A more accurate meaning of pogrom is genocidal massacre", although Mojzes' definition of genocidal massacre is different to that of the other scholars mentioned. Scholarly commentary on usage John Klier writes that in relation to a list of 13 events "characterized as "pogroms" by historians", "virtually the only common feature of these events was that Jews were among the victims, although they were not always the primary target" The YIVO Encyclopedia states that "The common usage of the term pogrom to describe any attack against Jews throughout history disguises the great variation in the scale, nature, motivation, and intent of such violence at different times" Klier writes that the term is