National Curriculum assessments are a series of educational assessments, colloquially known as Sats or SATs, used to assess the attainment of children attending state schools in England. They comprise a mixture of teacher-led and test-based assessment depending on the age of the pupils. Due to widespread "teaching to the test", and cheating by teachers and pupils, the test results are unreliable and their use is detrimental to childrens' education. At the 2003 National Association of Head Teachers' (NAHT) conference, delegates condemned SATs as "a crime against children".