The public may not be ready for the wholesale computerisation of Britain's exam system, according to the Westminster government's testing watchdog.
Researchers have also voiced concern about e-marking, saying examiners could lose concentration if they faced periods marking long scripts on-screen.
Ken Boston, chief executive of the Qualifications and Curriculum Authority (QCA), supports computerised exams and the digitisation of pupils' scripts to be marked on-screen, which he believes has the potential to transform Britain's "cottage industry" marking system.
But in a speech in Australia, he admitted that the "man on the Clapham omnibus" was not yet ready to accept rapid advances. "Is England ready to have A-level Shakespeare marked in Toronto or Brisbane?" he asked.
By 2010, the QCA wants pupils to be able to take some modules of most exams at the screen.
Other reforms include the chance for pupils to sit interactive computerised exams at a time of their choosing, and the use of markers around the world to mark longer answers on-screen.
But the issue of on-screen marking of essays is particularly contentious.
Edexcel, England's second-largest exam board, has embraced e-marking.
It marked four million GCSE, A-level and vocational papers on-screen, and the figure is due to rise next year. It said it has no plans to trial the marking of long answers overseas. But its examiners have marked longer essays on-screen.
Britain's largest board, AQA, which marked 750,000 GCSEs this year on-screen, said longer essays would not be marked electronically unless it was confident examiners could conduct a "proper evaluation" of students'
Cambridge Assessment, parent body of the OCR board, which is a rival of profit-making Edexcel, said more research was needed to check if examiners'
online judgements were accurate.
It found annotation was easier on paper than at the computer, and examiners found it easier to get an overall sense of a text by reading it on paper.
But there was no evidence of marking disparities between the two methods.
This summer, Welsh exam board the WJEC used on-screen marking for some exam papers in GCSE maths, ICT and AS-level computing.
Gareth Pierce, chief executive of the Welsh exams board, has previously said that technology should be used to "enhance the style of assessment, not change it".
Meanwhile, the QCA is at odds with Edexcel, after vetoing its plans to have some of this year's key stage 2 and 3 tests, taken by 1.2 million pupils, emailed to examiners and then marked on screen.