We've heard it many times. Australia is on a 15-year-slide in PISA, the Program for International Student Assessment, which measures the skill levels of 15-year-olds around the world in literacy and numeracy.
It's an issue which feeds the concern parents have about the quality of schooling. It's part of the reason why we see a long-term move out of public schools into non-government schools. 
Even though this four-decade movement halted this year, it's still happening in high schools where parents continue to look for Catholic or independent schools for their children. (Only in the primary schools is there a move back to public schools.)
And it is part of the reason why schools are a major issue in the election campaign. It's one of the areas where their is a clear difference between the Turnbull government and the Shorten opposition, with Labor promising an extra $3 billion for schools over the next three years, while the Coalition will limit its extra money to inflation increases in the cost of education.
But measured internationally, how bad is Australia's performance? The first thing to know is that yes, we are unambiguously getting worse.
In the 2003 PISA numeracy tests only four countries were significantly ahead of us (in an admittedly smaller sample of countries). In 2012, the most recent round of tests for which we have results, 16 countries were ahead of us. Australia slipped 20 points on the numeracy test score over this period.
It's a similar story for literacy. In 2000 only one country was significantly ahead of us but by 2012 four were. And we had dropped 16 points in the literacy test score over the period.
But how poor is our performance compared with other countries. In both literacy and numeracy we were still above the OECD average in 2012, in spite of the worsening performance. And we were ahead of the UK and the US on both measures. The US is particularly bad on numeracy.
The PISA test also measures science literacy and, in 2012, Australia was also above average on this measure and, again, ahead of the US and the UK. So, amid the general decline in education achievement in the English speaking world, Australia is not the worst.
But there is a group of countries and regions which Australia is consistently behind. In numeracy, literacy and science we significantly lag Shanghai, Hong Kong, Singapore, Japan, Korea and Finland.
If we aspire to be as good as the best countries in our regionwe are failing. The most alarming thing is that we are getting worse as other countries are improving.
The PISA test tells us how well our 15-year-olds are doing against other countries. But what about the skills of the whole working-age population. Another OECD survey called PIAAC, the Program for the International Assessment of Adult Competencies, measures literacy and numeracy among 16- to 65-year-olds.
A PIAAC survey in 2013 found that Australia was well above average in literacy, behind only Japan, Finland and the Netherlands. But in numeracy we don't do so well, coming in just below the average.
It's hardly an overwhelming endorsement of the skills of the Australian labour force. And because the performance of our 15-year-olds is in decline the skills of our whole working population will be getting worse.
At the moment the feeling among most Australian educators is that we are not improving. The PISA tests are done every three years.
The latest published results we have are for 2012 but the 2015 tests are now being processed for publication this   December. The results are awaited with anticipation, and some trepidation.