Perhaps your teacher is just a good a judge of your academic prowess as an exam paper – and that could help reduce some of the exam workload on kids as they go through school.
Researchers looked at data collected on more than 5,000 pairs of twins in the UK, and found that teacher assessments correlated strongly with exam scores across English, maths and science between from ages 7 to 14.
Additionally, teacher assessments were also found to accurately predict how students fared at GCSE and A-level exams (usually taken at age 16 and age 18, respectively).
"Teacher assessments account for ~90 percent of the combined prediction (teacher ratings and earlier test scores) of exam performance at ages 16 and 18," the team writes in the "key points" summary of their paper.
"We have shown for the first time that teacher assessments predict GCSE and A-level results just as well as earlier exam scores," says one of the researchers, Kaili Rimfeld from King's College London in the UK.
"The fact that exam scores correlate so highly with the teacher assessments raises questions about the value of the testing culture that characterises compulsory education in the UK."
In a novel twist on education research, the study was also able to factor in genetic influences on academic performance by tapping into an existing large-scale collection of data on UK twins.
"We have demonstrated a remarkably high agreement between teacher assessments and standardised tests, both phenotypically and genetically," the researchers conclude.
The use of exams from an early age to assess pupil progress continues to be a topic of controversy in the UK and elsewhere – there are questions over the pressure it puts on children and on teachers to meet targets.
As well as GCSEs at age 16 and A-levels at age 18, children in the UK take SATS tests at age 7 and age 11. The researchers are suggesting that some of that burden could be eased through the use of teacher assessments, as the results largely match.
"While testing can stimulate both pupils and teachers to focus their efforts, high-stakes exams may shift the educational experience away from learning towards exam performance," says one of the team, Margherita Malanchini from the University of Texas at Austin.
"For these reasons, we suggest that teacher assessments could be relied on for monitoring progress, instead of exam scores, in particular during earlier school years."
The team behind the study is keen to emphasise that exams should still play an important role in education, and that teachers shouldn't be given any extra workload – but that existing assessments could stand in for exams in some cases.
After all, the stakes are high: exam performance and educational standards play a big part in affecting the future direction of individuals and communities as a whole, the researchers point out.
"Our results should inform the debate about testing during both primary and secondary education," says Malanchini.
"Trusting teachers to implement the curriculum and monitor progress could benefit the well-being of pupils and teachers and help to bring joy back to the classroom."
The research has been published in the Journal of Child Psychology and Psychiatry.