Prof. Moshe Koppel is Emeritus Professor of Computer Science at Bar-Ilan University,  best known for his research on authorship attribution. Together with Shlomo Engelson Argamon and Jonathan Schler, he has shown that statistical analysis of word usage in a document can be used to determine an author's gender, age, native language and personality type. 
The findings regarding gender generated considerable controversy.
In recent years, Koppel has published several papers in social choice theory, offering (in joint work with Avraham Diskin) formal definitions of a number of concepts, including disproportionality, and voting power the definitions of which had been the subject of controversy. In related work, Koppel and colleagues have shown how the wisdom of crowds could be optimally exploited.[7] Along with Nathan Netanyahu and Omid David, Koppel showed that, using only records of games played by grandmasters, a chess program could be trained essentially from scratch to play at grandmaster level. A program designed by Omid David based on these ideas placed second in the speed chess competition in the 2008 World Computer Chess Championship.