The use of teacher assessed grades in 2021 has inevitably raised questions about whether allowing teachers to determine their students’ grades is a sustainable and viable model in the future.

However, while the challenges inherent in using teacher assessment in a high-stakes accountability system are a relatively novel debate in the world of secondary education, it is often forgotten that teacher assessment has been a regular fixture in primary education for many years.

In Key Stage 1 SATs at age 7, the externally-set mathematics and reading tests are marked by teachers, while pupils are also assessed by their teachers on writing, science and speaking and listening. The Key Stage 2 SATs in reading, mathematics and ‘grammar, punctuation and spelling’ at age 11 are externally set and externally marked, but teacher assessment is still used for judging pupil’s writing and science. The ‘phonics check’ for 6-year-olds is also delivered by classroom teachers.

Critics of SATs have long wanted to see them replaced by teacher assessment. A 2008 report from the Children, Schools and Families Committee in Parliament found that “many witnesses have called for greater emphasis on teacher assessment in order to enhance both the validity and the reliability of the testing system […and] provide a more rounded view of children’s achievements”. 

Similarly, the government-commissioned ‘Bew Review’ in 2011 noted that many respondents argued that using teacher assessment “would demonstrate trust in teachers’ professional skills, remove incentives for inappropriate test preparation or narrowing of the curriculum, and avoid judging schools through a ‘snapshot’ of data from one week of tests.”

It’s human nature. Humans use stereotypes as a cognitive shortcut and we’re all prone to it.

Tammy Campbell, author of Stereotyped at 7? Biases in Teacher Judgement of Pupils' Ability and Attainment

However appealing such a change may appear at first, research evidence from across the world suggests that teacher assessment is likely to be less valid and reliable than external tests and may even lead to worse outcomes for pupils from the most deprived backgrounds:

  • Burgess and Greaves (2009) found that teacher assessments “might be severely detrimental to the recorded achievements of children from poor families, and for children from some ethnic minorities”, while “external testing in some way protects pupils from typically low-attaining groups from subconscious assumptions.”
  • Using data for almost 5,000 pupils from the Millennium Cohort Study, research by Tammy Campbell in 2015 found “biases in teachers’ average ratings of sample pupils’ reading and maths ‘ability and attainment’” which corresponded to key demographic characteristics such as income-level, gender, special educational needs and ethnicity.
  • In 2011, a summary of research in the USA on teacher assessment found that “teacher classroom summative assessment, that is, teacher grading practices, have historically and currently emphasised the lack of validity and reliability of these judgements”. 
  • A 2016 meta-analysis in Australia found that “statistically significant” rates of bias “can occur …when graders are aware of irrelevant information about the students” including their racial / ethnic background, ‘education-related deficiencies’ and poor prior performance.

To be clear, none of the biases detected by research studies are intentional on the part of teachers. As Tammy Campbell, author of the 2015 study cited above, has said: “I want to stress that this isn’t something unique to teachers. It’s human nature. Humans use stereotypes as a cognitive shortcut and we’re all prone to it.”

The Bew Review had recognised there were “clear risks that summative teacher assessment will not be sufficiently reliable in a technical sense – i.e. that judgements will not be made consistently by teachers across the country”.  The Review also highlighted the “risk that teachers would come under increasing pressure to make generous assessments for some or all of their pupils.” 

In addition, a 2017 Education Select Committee inquiry into primary assessment “heard a wealth of evidence of the disadvantages of using teacher assessment within a high-stakes accountability system.”  One primary school teacher told the Committee that “teacher assessment for accountability, or in any high-stakes, or for any reliability purposes, is impossible […] because you are basically judging yourself.”

The significant workload burden that teacher assessment generates should also not be underestimated. This was recently emphasised by the teacher-assessed grades for GCSE and A-levels in 2021, with numerous reports emerging of the excessive demands generated by having to collect sufficient evidence of student performance. Primary teachers have been experiencing these same burdens for years.

Although there is no reason to simply withdraw teacher assessment from primary education, the research evidence does not support a concerted movement away from external testing and towards more teacher assessment in primary schools. When considering the future of secondary assessment and accountability, it would therefore be wise to compare notes with the primary sector to ensure that we do not ignore what has already been learned.

Read more on this subject:
Could comparative judgement replace traditional exam marking?
Comparative judgement: The pros and cons
How do we know home schooling is meeting the standard?


House of Commons Children, Schools and Families Committee, Testing and Assessment: Third Report of Session 2007–08 - Volume I.

House of Commons Education Committee, Primary Assessment: Eleventh Report of Session 2016–17.

Malouff, J M. and Thorsteinsson, E B. (2016) Bias in Grading: A Meta-Analysis of Experimental Research Findings, Australian Journal of Education 60(3), 245–56.

Department for Education. (2011). Independent Review of Key Stage 2 Testing, Assessment and Accountability: Final Report [Independent Review. Review of key stage 2 testing, assessment and accountability - GOV.UK (

Lewis, L. (2021, May 20). My Life Right Now? Marking, Marking and More Marking, Times Educational Supplement.GCSEs and A levels 2021: We're in a hell of teacher assessment | Tes ; Anonymous. (2021, March 16). Why GCSEs 2021 Are Another Shambles Waiting to Happen, Times Educational Supplement. GCSEs and A levels 2021: Why teachers are in the firing line | Tes

Adams, R. (2015, June 9). Children from Poorer Families Perceived by Teachers as Less Able, Says Study, The Guardian. Children from poorer families perceived by teachers as less able, says study | Primary schools | The Guardian

Burgess, S. & Greaves, E. (2013) Test Scores, Subjective Assessment and Stereotyping of Ethnic Minorities, Journal of Labor Economics, 31(3), 535-576.

Brookhart, S M. (2013). The Use of Teacher Judgement for Summative Assessment in the USA, Assessment in Education: Principles, Policy & Practice, 20(1), 69–90.

Campbell, T. (2015) Stereotyped at Seven? Biases in Teacher Judgement of Pupils’ Ability and Attainment, Journal of Social Policy, 44(3), 517–47.