The distribution has a local mode at six grades (29%% of the individuals), completion of primary school.
"Except for those two little ones right here," he joked, pointing at two grade-schoolers in the front row.
At eight-grade students from the intervention school scored significantly higher on the SAT10 and reported higher interest in science.
TIMSS was first conducted in 1994/1995, in 45 countries, at five grade levels (3, 4, 7, and 8, and the final year of secondary school).
Last summer an impressive 79% of students achieved at least five grades at A*-C, including English and maths – a big improvement on the 64% in 2013 and 56% in 2012.
Students do not change schools, and at the elementary level, usually have the same teacher for at least four grades.
Now Roy, who is at least three grades behind and needs special education, tutoring and counseling, can hardly be persuaded to leave school when the last bell rings.
The proportion of pupils gaining at least five grades A* to C has shot up from 55% to 81% since 2004-05.
At the very top for GCSE results was Colyton grammar school in Devon, where all 117 GCSE pupils got at least five grades C or higher, including English and maths.
West London free school pupils performed well in the school's first set of GCSE results this summer, with 76% of the first cohort to sit the exams getting at least five grades of C or better, including English and maths.
