Principals and teachers have long thought that student tardiness was a serious problem. In one study from the 1990s, 8-12% of students were absent each day, and more than 40% of teachers found tardiness to be a significant problem. In fact, it is considered so serious that a school's response can go to extremes. The question, of course, is not "what are high schools doing?", but "what are high schools doing that's working?" Many approaches seem to work, but they tend to break into two categories: the behavior modification approach and the needs-based approach. Behavior modification approaches include the following: being locked out of class; detentions; parent conferences; additional assignments; reductions in grades; work details during lunch, after school, or free periods; Saturday classes; token systems for being on time; time cards; time management workshops; contingency contracts; and tardy rooms. Many of these strategies proved effective, but detentions, reduced grades, tardy rooms, and additional assignments proved ineffective at changing behavior. Other schools, however, look at the reasons that students are tardy and try to address the underlying problems. This approach is based on the idea that before a school can change the behavior of at-risk students, they must understand what is going on in those students' lives. When asked through interviews or surveys, students indicated that they were tardy for the following reasons: transportation problems; overcrowded conditions; lack of positive history about people of color; lack of a culturally sensitive curriculum; dirty and limited access to bathrooms; health-related causes; sleeping habits; and family-related excuses. Successful needs-based strategies included the following: identifying chronic offenders, assessing them individually, and referring them to appropriate services, including support groups; working with parents to find solutions; instituting free breakfast programs; working with teachers to improve the quality of the instructional program; switching to Block scheduling; interdisciplinary & integrated curriculum; and providing opportunities for students to express their opinions and contribute to the operation of the school. Needs-based approaches had the added benefit of not only improving punctuality, but often academic achievement and attitude toward school, as well. (Contains 15 online resources.)