The introduction of personal learning planning for children at some Scottish schools has increased the workload on teachers, according to a union survey.
The unions surveyed teachers involved in pilot schemes
The Educational Institute of Scotland (EIS) said 83% of those questioned said new demands had been placed on them.
The union said many of its members had experienced a bureaucratic burden which reduced time available for teaching.
But the Scottish Executive said it was up to individual schools to decide how to implement the scheme.
Personal learning planning, in which youngsters help develop a plan suited to their own skills and abilities, is being piloted at a number of Scottish schools.
A spokesman for the executive said the scheme was not a bureaucratic reporting mechanism.
"We talk about personal learning planning - not plans," he said.
"It is up to individual schools to decide how to take this forward."
The EIS commissioned its study into pilot schemes for personal learning planning.
George MacBride, the union's education convener, said: "Teachers in many areas across the country report that the PLP process has resulted in a significant bureaucratic burden with a reduction in the time available for teaching and few obvious benefits for pupils.
"The results of this survey clearly indicate that, while teachers can see the possible benefits of PLP for pupils, they are worried that the scheme could prove unworkable unless proper steps are taken to address the problem of the additional workload which is being created.
"If local authority representatives and school management teams do not pay heed to what teachers are saying, PLP will ultimately fail."