Figure 7. Change in average science scores of 8th-grade students, by education system: 20072011 and 19952011
Score is higher than U.S. score.
Score is lower than U.S. score.
Change from 2007 to 2011.
Change from 1995 to 2011.
# Rounds to zero.
*p<.05. Change in average scores is significant. 1 The change in average score is calculated by subtracting the 2007 or 1995 estimate, respectively, from the 2011 estimate using unrounded numbers. 2 National Defined Population covers 90 to 95 percent of National Target Population for 2011 (see appendix A). 3 Nearly satisfied guidelines for sample participation rates after replacement schools were included for 2011. 4 National Target Population does not include all of the International Target Population for 2011 (see appendix A). 5 Exclusion rates for Georgia are slightly underestimated as some conflict zones were not covered and no official statistics were available for 2011. 6 The TIMSS International Study Center has reservations about the reliability of the average achievement score because the percentage of students with
achievement too low for estimation in 2011 exceeds 15 percent, though it is less than 25 percent.
NOTE: Education systems are ordered by 2011 average scores. Italics indicate participants identified and counted in this report as an education system and not
as a separate country. All education systems met international sampling and other guidelines in 2011, except as noted. Data are not shown for some education
systems because comparable data from previous cycles are not available. Participants that did not administer TIMSS at the target grade are not shown; see the
international report for their results. All U.S. state data are based on public school students only.
For 1995, Lithuanias National Target Population did not include all of the International Target Population; the Russian Federation and Lithuania had a National
Defined Population that covered 90 to 95 percent of National Target Population; England-GBR, and Ontario-CAN had a National Defined Population that covered
less than 90 percent of National Target Population (but at least 77 percent); the United States, England-GBR, and Minnesota-USA met guidelines for sample
participation rates only after replacement schools were included. For 2007, Lithuania, Georgia, and Indonesia had National Target Populations that did not include
all of the International Target Population; the United States, Massachusetts-USA, Minnesota-USA, and Ontario-CAN had National Defined Population that covered
90 to 95 percent of National Target Population; Hong Kong-CHN, England-GBR, and Minnesota-USA met guidelines for sample participation rates only after
replacement schools were included; Dubai-UAE nearly satisfied guidelines for sample participation rates after replacement schools were included.
All average scores reported as higher or lower than the U.S. average score are different at the .05 level of statistical significance. The tests for significance take
into account the standard error for the reported difference. Thus, a small difference between averages for one education system may be significant, while a large
difference for another education system may not be significant. Detail may not sum to totals because of rounding. The standard errors of the estimates are shown
in table E-25 available at http://nces.ed.gov/pubsearch/pubsinfo.asp?pubid=2013009.
SOURCE: International Association for the Evaluation of Educational Achievement (IEA), Trends in International Mathematics and Science Study (TIMSS), 1995,
2007, and 2011.