The relationship between lesson characteristics and the improvement of the delivery of educational services to Hispanic Americans was examined, using data from four contrasting classrooms (two successful and two unsuccessful) located in a Southern California medium-sized school district. The contrast between classrooms was determined by the characteristics of the lessons contained within each classroom. One successful and one unsuccessful classroom was constituted primarily of Hispanic American students while one successful and one unsuccessful classroom was heterogeneously constituted. Four teachers were observed and interviewed; three principals were interviewed to identify classrooms and to verify the teachers' teaching styles and competencies. Lesson plans, curriculum guides, and inservice bulletins were collected and analyzed. Data were obtained on the types of lessons (teacher-led verbal, activity, practice drill, testing); lesson content (teacher elicitation, student response, teacher evaluation); form and structure of lessons (demarcation, opening, lesson content, closing); and mix of lesson types. Findings indicated that: adherence to the structure of lessons accentuated teaching; successful classrooms conducted teacher-led and activity lessons to a greater degree; the enactment of the classroom culture was facilitated by adherence to lesson structure; and ethnic composition did not affect the classroom's success as did adherence to lesson structure. (NQA)