An excessively broad school curriculum was creating "a treadmill of learning for teachers and [pupils]', Prof Crooks said in a University of Otago graduation address at the Dunedin Town Hall on Saturday.
"It is hard to make learning interesting if schools are trying to cover too much."
Prof Crooks, who is co-director of the university's Educational Assessment Research Unit, made his comments to about 220 people who had just graduated from the university, mainly with qualifications in education and teaching.
At its best, teaching was not a job but a vocation, demanding passion, persistence and clarity of purpose, he said.
The school curriculum kept broadening and in the past 15 years technology, dance and drama had been added as required subjects.
Other areas that used to begin in intermediate or high school were now included also in the early years and areas of community concern were often proposed as additions to school programmes.
"Quantity of learning is threatening quality of learning," he warned.
The revised curriculum offered teachers and schools a chance to be more selective about what they tried to teach.
"This opportunity must be grasped.
Covering fewer topics more richly each year will not threaten what can be achieved over 13 or more years of early childhood education and schooling."
At present, the same topics, knowledge and skills were addressed repeatedly so that pupils often became sick of them.
Covering less each year would allow time to explore topics in more interesting ways, give more opportunities for pupils to make choices from a range of options, and give teachers more space to work intensively with individual pupils, he said.
Schools should not have to take all of the blame for a loss of motivation and confidence in the learning ability of some pupils.
"The overall educational achievements of our children clearly depend more on family and community contributions than on schools," Prof Crooks said.
Nevertheless, something had to be done to make education stimulating and motivating for all or almost all children, particularly in the middle years of schooling, he said.
