some higjhperforming countries in pisa such as estonia and finland also show small variations in student scores proving that high performance is possible for all students oecd a for students who fail to reach this level of performance in mathematics reading or science most can be expected to not continue with education beyond compulsory schooling and therefore risk facing difficulties using mathematics reading and science concepts throughout their lives and risk having poorer opportunities in the labour market even in the average oecd country where more than one in five students do not reach level tackling such low performance is a major challenge that requires addressing barriers posed by factors such as social background