Exhibits 10.10, 10.11, 10.12, and 10.13 present teachers’ reports about the extent to which their fourth and eighth grade classroom teaching is limited by students not ready to learn (i.e., lacking prerequisite knowledge or skills, lacking basic nutrition, being sleep deprived, absent, disruptive, or uninterested, or having learning impairments or difficulties understanding the language of instruction), along with student achievement. The results are summarized on the Classroom Teaching Limited by Students Not Ready for Instruction scale described in Exhibit 10.9 (see About the Scale), with three categories that describe how much classroom teaching is limited: “very little,” “some,” and “a lot.” A higher score on the scale indicates that classroom instruction was limited less by these student attributes or behavior, and a lower score indicates it was limited more. Countries are sorted by the percentage “very little.”

On average, across countries, just over one-third of the fourth grade students (36% for mathematics and 37% for science) had classroom teachers who reported that their teaching was limited “very little” by students not ready for instruction. Most of the rest of the students (59% in mathematics and 58% in science) had teachers who reported that instruction was limited “some.” Unfortunately, 6 percent of students were in classrooms where teachers reported instruction was limited “a lot.” The picture was even less positive in eighth grade, where only about one-quarter of students (24% in mathematics and 26% in science) had teachers who reported that classroom instruction was limited “very little,” and about two-thirds (67% for mathematics and 66% for science) had teachers who reported that classroom instruction was limited “some” by students not ready for instruction. The remaining 8–9 percent of students (9% in mathematics and 8% in science) had teachers reporting instruction was limited “a lot.”

In both subjects and both grades, there was a direct relationship between the degree that instruction was limited by students not ready for instruction and students’ average achievement, with successively lower achievement for each category of increased impact on teaching. For example, in eighth grade science (Exhibit 10.13), average achievement was 515 for students where instruction was limited “very little,” 484 for students where instruction was limited “some,” and 457 for students where instruction was limited “a lot.”