Preliminary NAPLAN results released on Tuesday show results across NSW for all five testing areas – reading, writing, spelling, numeracy, and grammar and punctuation.

The tests are compulsory for students in Year, 3, 5, 7, and 9 and data shows more primary schools students met the minimum national standard than those in high school.

Almost one-fifth of Year 9 students in NSW failed to meet the minimum benchmark in writing during the 2018 NAPLAN test.

Just 81.3 per cent of NSW students tested met the minimum, however, this was higher than the national average score of 79.5 per cent.

The percentage increased for those in lower years, with 88 per cent of Year 7 students in NSW hitting the benchmark, following by 91.4 per cent of Year 5 students and 95.7 per cent in Year 3.

All year groups recorded a fall since testing in 2017.

In spelling, 95.1 per cent of Year 3 students and 94.9 per cent of Year 5 students hit the benchmark, this was a slight increase on last year.

However, in high school years the standard fell slightly to 93.4 per cent in Year 7 and 91.2 per cent in Year 9.

The only subject where all year groups recorded an increase was grammar and punctuation. The national minimum was met by 95.3 per cent of Year 3 students, Year 5 (94 per cent), Year 7 (92.7 per cent) and Year 9 (92.2 per cent).

While the NAPLAN results were an interesting and useful for planning school resources, NSW Teachers Federation country organiser Kelly Anderson said they were only a “snapshot in time” and should not be the principal focus for assessing a student’s overall success.

“Overall performance is what we’re concerned about,” she said.

“These [NAPLAN tests] are just a one-off snapshot.”

Ms Anderson said while the five testing areas are important, there are many areas in students’ lives that were not tested.

“Music and science abilities, PE and sporting, these areas are not even considered,” she said.

Ms Anderson said there was often more government funding for students in primary schools, rather than in high schools, and this could be the reason why younger students out-performed older ones.