Bevan RM, Daugherty R, Dudley P, Gardner J, Harlen W & Stobart G (2004) A Systematic Review of the Evidence of Reliability and Validity of Assessment by Teachers Used for Summative Purposes. EPPI-Centre, University of London. https://eppi.ioe.ac.uk/eppi/Evidence/EPPI_reviews/Assessment/Review3/ass_rv3.pdf
First paragraph: The reason for proposing this review resulted from the work of the Assessment Reform Group (ARG) over several years and the more recent reviews conducted by the Assessment and Learning Research Synthesis Group (ALRSG), whose members include all the members of ARG. The review of classroom assessment initiated by ARG, and carried out by Black and Wiliam (1998), indicated that assessment used for formative purposes benefits teaching and learning, and raises standards of student performance. However, the ALRSG review, A systematic review of the impact of summative assessment and tests on students' motivation for learning, showed that high stakes tests can have a negative impact on students' motivation for learning and on the curriculum and pedagogy. But, summative assessment is necessary and serves important purposes in providing information to summarise students' achievement and progress for their teachers, parents, the students themselves and others who need this information. To serve these purposes effectively, summative assessment should interfere as little as possible with teaching methods and the curriculum and, importantly, should reflect the full range of learning outcomes, particularly those needed for continued learning and for learning how to learn.