sentences:  Koffman's early research was in artificial intelligence and intelligent tutoring systems.In 1974 he began writing and co-authoring textbooks for introductory programming courses for computer science majors (CS1) in programming languages such as Ada, BASIC, C, C++, Fortran, Java, Modula-2, and Pascal.He also wrote textbooks for the first data structures course (CS2) in C++, Java, and Pascal.