Science practices, and in particular scientific inquiry and investigation knowledge and skills, are important components of many science curricula. Teachers were asked the frequency with which they have their students engage in various instructional activities related to science investigations and experiments. Responses were combined into the TIMSS Teachers’ Emphasis on Science Investigation scale, described in Exhibit 13.11 (see About the Scale), to report two categories: “about half the lessons or more” and “less than half the lessons.” Results of teachers’ reports are presented in Exhibits 13.12 and 13.13 for fourth and eighth grades, respectively, together with students’ average achievement. Countries are ordered by the percentage of students in “about half the lessons or more.”

On average, 31 percent of fourth grade students had teachers who reported an emphasis on science investigation in “about half the lessons or more,” and 69 percent had teachers who reported an emphasis on science investigation in “less than half the lessons.” Average achievement was similar for students in both categories of emphasis. Just 27 percent of eighth grade students were taught by teachers reporting an emphasis on science investigation in “about half the lessons or more,” and 73 percent had teachers who reported an emphasis on science investigation in “less than half the lessons.” In eighth grade, average achievement for students in the “about half the lessons or more” category was 492, and was 490 for those in the “less than half the lessons” category.