The reading skills of Scottish children have fallen in a major international league table of literacy.
The study looks at data from children, teachers and parents
Scotland, which was in 14th place in 2001, fell to 21st in the research, run by Boston College in the US.
The reading performance of children in England fell from third to 15th. Russia came out top of the table.
The Progress in International Reading Literacy Study (Pirls), undertaken every five years, involved children aged about 10 in 40 countries.
Defined as the ability to understand and use those written language forms required by society and/or valued by the individual
Pirls is designed to investigate children's "reading literacy" and associated factors after, in most countries, four years of formal schooling - five in England and Scotland.
First run in 2001, it involves data from a sample of pupils, their parents and their teachers and head teachers.
As well as a drop in the overall reading achievement ranking, it found a significant decrease in the proportion of children in Scotland who had the most positive attitudes to reading.
The number of Scottish children who reported playing computer or video games for more than three hours a day was one of the highest, at 38%.
However, teachers of nearly all pupils in Scotland reported using a reading scheme at least once a week.
In New Zealand, Scotland and the US more than 90% of pupils were also found to have a library or reading corner available in their class, higher than England at 84%.
Only 65% of pupils in Scotland said they liked being in school, one of the lowest approval ratings in the survey, and 5% lower than in England.
Scotland's Minister for Schools and Skills Maureen Watt stressed that she was pleased that the findings showed the most able pupils ranked amongst the highest achievers in parts of the international study.
The minister said Scotland's reading literacy was still significantly above the international average.
"However, there is much to do to close the gap between the best and worst performers in Scotland which has remained persistently large," she added.
"The report also shows what this government already knows - that pupils in schools in areas of deprivation don't do as well.
"We are determined to improve the situation we have inherited."
Judith Gillespie, of the Scottish Parent Teacher Council, called for literacy to be made a "number one" priority.
Earlier this year, West Dunbartonshire Council claimed to be the first local authority in the world to eradicate illiteracy in its schools, using a system of teaching by word sounds, or synthetic phonics.
Ms Gillespie called for its methods to be replicated.
She said: "It's focussed. They're using teaching methods which deliver and they're monitoring the children carefully - then giving extra support to those who need it.
"They don't say if children haven't learnt - that's the way it is - and let it go."
Conservative Schools and Skills spokeswoman Liz Smith echoed the statement.
She said: "Councils should encourage their schools to adopt this practice - basic teaching such as the 3Rs are one of the most important things we can advocate.
"It certainly matters to children in later life, whether they are going into work or higher education after school."
Liberal Democrat education spokesman Jeremy Purvis said: "This demonstrates the continuing need for growth in investment for Education in Scotland.
"There is now no doubt that as a proportion of overall government expenditure, education has slipped down the government?s list of priorities."