The TIMSS 2015 international results were released on November 29, 2016.
TIMSS 2015 involved 60 countries and benchmarking regions. The study assessed more than 600,000 students across grade four, grade eight and advanced mathematics and physics students in their final year of secondary school.
In reaching its 20 year milestone, TIMSS earned the distinction of establishing the longest trend line of any international education assessment.
The TIMSS 2015 reports are available from the TIMSS & PIRLS International Study Center:
TIMSS 2015 International Results in Mathematics
TIMSS 2015 International Results in Science
TIMSS Advanced 2015 International Results in Advanced Mathematics and Physics
This World Bank blog post also presents a useful overview of the findings.
IEA Executive Director, Dr Dirk Hastedt summarises the key findings from IEA's TIMSS, the longest-running, large-scale international assessment of mathematics and science education in the world.
"Twenty years of trends offers three remarkable findings: gender gaps in achievement have narrowed, schools are now perceived to be safer places than in the past; and students consistently report high levels of self-confidence and enjoyment in mathematics. We are happy to convey such positive news."