As with elementary and middle schools, high schools’ performance is affected by teacher quality, a strong curriculum, effective leaders, and a rigorous process for monitoring which students need additional assistance.

As the final stop in K–12 education, high schools are sometimes presented with students who, for a variety of reasons, have not mastered the skills needed to excel at the high school level. The reading and math skills learned in elementary school help students to succeed in middle school, where they further build on those skills to prepare for high school. If students arrive at the next level of schooling without the proper skills, it is harder for them to keep up academically. This leaves educators with the dilemma of how to improve students’ basic skills while also covering the high school curriculum. Likewise, students face the frustration of trying to master higher-level material without the academic foundation needed to do so. Further, some students are not engaged by the subject matter or how it is taught. Underprepared and disengaged students often lose interest in school and drop out. Once they have, it is difficult to entice them to return.

High schools must also manage two major transitions for students—from middle to high school and from high school to college, jobs, or work preparation programs. This takes considerable coordination. When they start high school, new students face social transitions plus rules, schedules, and expectations that may be different from those in their middle schools. High schools must help students understand that how they manage these changes will affect them before and after graduation.

In addition, high school students are more socially and intellectually sophisticated than their younger counterparts and require a different kind of attention to keep them engaged in learning. The National Governors Association’s 2005 online survey, "Rate Your Future," which gathered responses from more than 10,000 high school students nationwide, found that many of those surveyed say that high schools could be improved. Of students planning to graduate from high school, approximately one-third think high school has been easy and “strongly agree” they would work harder if the courses were more challenging and interesting. Of students who have dropped out or are considering dropping out, 66% say that personal attention to help them with their studies would have helped them to stay in school. A 2005 Public Agenda study, "Life After High School," found that 18- to 25-year-olds confirm many of these views.

Further, improving high schools is difficult because their scope and scale are large. Part of the comprehensive high school’s mission—“to be all things to all people”—usually requires a larger school to maximize economies of scale. Providing personal attention for all students can be a challenge because teachers may interact with as many as 150 students per day—30 students in the average class and five daily class sessions. In addition, high schools tend to divide teachers by subject area. Coordinating high school teachers and disciplines is inherently more complicated than in an elementary school where three teachers might manage the entire third grade.