MELBOURNE, Aug 2 - A decline in Victorian school students' writing skills could be linked to the increasing use of technology, the state government says.

Preliminary 2017 NAPLAN results show Victoria's year nine students have gone backwards in writing during the past five years.

Years three, five and seven have made no improvement over the same period.

Education Minister James Merlino says technology is an issue and a balance needs to be struck to ensure students can still write despite the shift to digital-based learning.

"I get concerned if there's too much focus on technology and devices and I also get concerned if there's no focus on technology at all," Merlino told ABC radio on Wednesday.

"Education ministers all around the nation...(are) very firm in the belief that we have to continue (with) primary school-level writing being handwriting."

Victoria continued to show strong results for students above the national minimum standard, with primary school grades particularly strong.

The state had the best average scores for reading in all age groups and strong spelling skills but was in the middle of the pack when it came to numeracy.

Public schools association Parents Victoria said primary-school aged children had been observed trying to turn a magazine page by sliding their hand across it or attempting to enlarge a physical photo with their fingers like on smart devices.

The association said while technology influenced how students learnt, the extent of this was not clear.

But the Australian Industry Group said employers were watching their employees' literacy and numeracy standards decline.

"One Ai Group member told me this week that only one in five young people they interviewed recently for apprenticeships passed their simple factory maths test," chief executive Innes Wilcox said.

"This is a fairly typical experience among employers who are frustrated at the literacy and numeracy standards among secondary school graduates seeking employment."

Shadow education minister Nick Wakeling said parents would be disappointed with the NAPLAN results. 

"Despite the extra billions of dollars the government has spent on education these results are very modest," he said.

Detailed NAPLAN results, including individual school performance, will be released in March.