A psychologist who\'d been studying school programs in math and science, Berry joined Iverson\'s team at the IBM Research Center in Yorktown Heights, NY, in 1966 to work on the uses of APL in education. Jointly with the IBM Research Center in Bari, Italy, he wrote several papers on the uses of the APL language as a means of expression and explanation. At IBM and later at I. P. Sharp Associates, he wrote APL reference manuals that combined accuracy and readability.