A Study of Grammar-Concept Understanding Problem in C Programming Learning Assistant System

C programming is taught in introductory programming courses in many universities across the world. To assist self-studies of novice students, we have developed C programming learning assistant system (CPLAS). In this paper, we study the grammar-concept understanding problem (GUP) in CPLAS for first-step studies of understanding grammar concepts in C programming. Each question describes the definition of a keyword in a source code and requests to answer it. Any answer is verified through string matching. If a student cannot answer questions, he/she does not understand basic concepts and may be lost in C programming study. For GUP, we selected 66 keywords with questions, and generated 35 instances that cover them. The assignment results to 130 undergraduate students in Okayama and Nihon Universities revealed the difficult keywords and learning progresses of students.