Students who marry or have children, or who have had problems with the law or school authorities, are also at greater risk. Academic factors are clearly related to dropping out. Students who received poor grades, who had repeated a grade, who were overage for their class, and who had poor attendance for reasons other than illness were more likely to drop out. Poor attendance, failing grades, and low overall GPA marked these students' high school careers. Unfortunately, uncontrolled variables complicate the process of accurately identifying dropouts, as we shall see below.
Definitions vary among states, districts, and even among schools within the same district.
In addition, the criteria used to define dropout are sometimes questionable, resulting in statistics that don't accurately reflect the problem. For example, some institutions count as dropouts students who transfer to other schools, are hospitalized, take longer than four years to graduate, or are admitted early to college. Some don't count students who leave to get married, who attend for four full years, or who exceed the compulsory attendance age but haven't fulfilled graduation requirements. When the count is made also affects the totals. In addition, the interaction of multiple, complex variables makes it hard to determine which ones are significant.