During the first phase of a three-phase study of teaching basic reading skills in the secondary schools, 43 secondary-school reading classrooms were observed for three days, and the relationships between teaching processes and students' gains in reading were examined. Data were recorded with the Secondary Observation Instrument, and the Classroom Environment Scale was used to obtain students' perceptions of the instructional process. Student reading achievement scores and absence rates were also recorded. Analyses of the data indicated that (1) teacher reinforcement of correct responses and guidance for incorrect responses were positively related to reading achievement gains; (2) the frequency of reading related verbal interactions, including interactive instruction and oral reading, positively related to achievement; (3) the number of social interactions and off-task behaviors that occurred during the class had a negative relationship to achievement; and (4) a relationship existed between positive effect recorded in the classroom and student absence rates, with lower student absence rates associated with more positive and supportive classroom environments. Furthermore, greater gains in reading achievement were associated with these environments. (HOD)