And the greatest collapse in results has happened in the ACT.

The Australian Curriculum Assessment and Reporting Authority has delivered a stark warning alongside the latest report on student assessment in ICT - that Australia's level of computer literacy in Year 6 and Year 10 is in decline and "warrants serious attention."

It has suggested that one of the reasons for the fall in standards is the increasing use of communications devices among young people and the assumption that they are able to also manage and process information.

Indeed, the majority of 10,562 students who took place in the online testing in October and November last year expressed confidence in using social media, downloading music and uploading files to a website. But only one fifth were confident in creating a database, constructing a web page, or using anti-virus software.

In the same way the authority monitors literacy and numeracy achievement through NAPLAN, ACARA has also been monitoring ICT literacy since 2005.

While performance in Year 6 and 10 increased steadily between the first test in 2005 to 2011, performance has fallen substantially between 2011 and 2014.

Nowhere has performance slipped more so than in the ACT, which provided 641 students from across 40 government and non-government schools for the assessment.

The ACT posted the single largest drop in achievement of any state or territory across both Years 6 and 10. ACT results are still generally stronger than average, however, with the ACT beaten only by Victoria in Year 6 and by Western Australia in Year 10.

Nationally, just over half, or 55 per cent of Year 6 students in 2014 reached or exceeded the proficient standard.

For example, Year 6 students were asked to search a website to find appropriate material, format a document, crop an image and create a short slide show. Students in Year 10 were asked to design an online survey, use software to add two new levels to an online game and create a short animated video.

By Year 10, just 52 per cent of Australian students were assessed as able to reach or exceed the proficient standard.

Their results show a significant decline in the mean performance compared with the last assessment in 2011. There has also been a reduction in the percentage of students in each year level meeting the proficient standards.

At the national level, the average scale score among Year 6 students was 22 points lower than in the previous assessment in 2011, which is a statistically significant difference, according to ACARA.

The most statistically significant decrease took place in the ACT, which lost 36 points between 2014 and 2011, followed by NSW which lost 33 points and Queensland which lost 21 points.

The ACT had the biggest fall of any jurisdiction in its average score between 2014 and 2008 when it lost 43 points. The next largest drop was recorded in Tasmania, which lost 23 points, while South Australia lost 17 points.

At Year 10 level, the national average scale score was 39 points lower than in the previous assessment in 2011 while the ACT lost 47 points.

When 2014 results are compared with 2008, that loss of points blows out in the ACT to 62, followed by NSW which lost 52, and Queensland which lost 44.

According to the report "One of the possible interpretations of the decline in ICT literacy is that the increased use of mobile technology devices has resulted in less emphasis on skills associated with information management and processing but more emphasis on communication applications.

"It is also possible that there has been less emphasis placed in schools on the teaching of skills associated with ICT literacy, with the development of young people's ICT literacy competencies increasingly being taken for granted. Such a shift in emphasis may have contributed to changes in ICT literacy achievement between 2011 and 2014.

"The reasons for the decrease in Year 6 and Year 10 students' ICT literacy levels remain issues for further investigation."

Chair of COAG's Education Council and Queensland Education Minister Kate Jones said "There is a risk that, as students increase their use of digital technology, assumptions will be made about their level of ICT expertise and knowledge."

A spokesman for the ACT Education Directorate said the ACT would work with ACARA and other jurisdictions to further explore the reasons for the decline in results.

He said the directorate was also undertaking "a significant change in the way technology is accessed and delivered across all ACT Public Schools to make it easier for teachers and students to integrate ICT across the curriculum". This included using Google Apps for Education (GAFE) where teachers could integrate a wide range of ICT tools in their teaching.