Challenging authority might be a youthful rite of passage but explaining which rules are most annoying has many school students perplexed.

Preliminary NAPLAN results from this year’s test showed some students were stumped by a writing task that asked which law or rule should be made better.

Victorian students in years 5, 7 and 9 recorded markedly worse scores than three years ago in persuasive writing.

Their results were only slightly worse than last year but the performance of year 3 students fell in persuasive writing compared to 2013.

This year 72.9 per cent of Victorian year 7 students exceeded national minimum standards in persuasive writing compared with 82.5 per cent in spelling.

Australian Curriculum and Assessment and Reporting Authority chief executive Rob Randall said there has not been an overall decline in writing standards. He said the writing task “didn’t engage” some students.

But the authority is also investigating whether the decline in persuasive writing occurred because for the first time schools were not told in advance whether the writing test would include a narrative or persuasive task.

“We have some evidence of a small increase in zero scores awarded to some students,” Mr Randall said. “This might mean that some students either did not understand the task or they were expecting a narrative task.”

However, students in Victoria were typically among the strongest performers in persuasive writing of all states and territories.

The preliminary NAPLAN data also shows a slightly lower proportion of Victorian students are at or above minimum standards in all the areas tested than they were in 2011 at year 3 and 9 levels.

But a higher proportion of students in Victoria are at or above minimum standards in all areas and across all year levels compared with the national figures.

Average performance in numeracy, reading, spelling and grammar and punctuation has remained steady in most states over the past three years of testing.

More than 1 million Australian students sat the tests in May.

Victorian Education Minister Martin Dixon said parents could be confident children were developing “vital skills for life”, including literacy and numeracy.

“But we must continue to drive improvement, from early years primary schooling through to senior secondary and beyond,” he said.  

NAPLAN scores for individual schools are published on the My School website.

Before the federal election Education Minister Christopher Pyne promised to review the website’s publication of each school’s NAPLAN results.

A spokesman for Mr Pyne said the Minister had asked the Education Department for advice on the presentation of information on the website.

“It is anticipated this analysis will be finalised before the end of the year,” he said.

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