This study examined the relationship of different assignment structures (i.e., teacher-constructed and student-constructed) on the achievement patterns of 6th-grade gifted and advanced students in a Southwest suburban school. Through a descriptive case study design (Berg, 2004; Merriam, 1988), an action research approach (Stringer, 2004) and self-study methods, the teacher-researcher explored student perception of control, and its influence on motivation (i.e., achieving and underachieving performance patterns) for different assignment structures. Findings indicate that gifted underachievers and advanced underachievers, alike, preferred the student-constructed assignment structure and self-assessment. The majority of gifted achievers and advanced achievers preferred the student-constructed assignment structure as well; however, they were evenly divided on their preference of the teacher assessment and the self-assessment. (Contains 1 table.)