TIMSS, conducted by the International Association for the Evaluation of Educational Achievement (IEA), is a worldwide research project that measures trends in mathematics and science achievement at the fourth and eighth grades (e.g. students aged 9-10 and 13-14). It has been conducted on a regular four-year cycle since 1995. In general, participating countries use TIMSS in various ways to explore educational issues, including among others monitoring system-level achievement trends in a global context, establishing achievement goals and standards for educational improvement, and stimulating curriculum reform.