The Instruction Affected by Mathematics Resource Shortages scale, described in Exhibit 6.13, summarizes principals’ reports about two kinds of resource shortages affecting instruction: general school resources and resources specific to mathematics instruction (see About the Scale). In Exhibit 6.14, countries are ordered (from most to least) according to the percentage of fourth grade students in schools “not affected” by resource shortages, from a high of 68 percent in Korea to a low of 0 percent in Kosovo. On average, 26 percent of fourth grade students attended schools “not affected” by resource shortages, and they had the highest average mathematics achievement (514). Sixty-eight percent of the students were in schools “somewhat affected” by resource shortages, and 6 percent were in schools “affected a lot.” Average mathematics achievement for these two groups was 499 and 473, respectively.

Exhibit 6.15 presents the results of the Instruction Affected by Mathematics Resource Shortages scale for eighth grade students. Similar to fourth grade, the percentage of students in schools “not affected” by resource shortages ranged from a high of 73 percent to a low of 2 percent, with an average of 30 percent. Sixty-three percent of the students were in schools “somewhat affected” by resource shortages, and 7 percent were in schools “affected a lot.” As in fourth grade, average mathematics achievement was highest for students in schools “not affected” by resource shortages (509), next for students in “somewhat affected” schools (483), and lowest for students in schools that were “affected a lot” (476).