School based assessment is the process by which a school systematically gathers, interprets and uses evidence about pupils' learning, attainment, progress or other educational outcomes. It can include teacher assessment, classroom questioning, assignments, practical tasks, projects, examinations, tests, observations, portfolios and other forms of evidence generated within the educational setting. The term distinguishes assessment conducted as part of school activity from assessments administered independently by external bodies, although schools can also administer standardised external tests.
School based assessment may be formative, helping teachers decide what to teach next, or summative, contributing to judgements about attainment at the end of a unit, course or period. It can also support diagnostic purposes by identifying misconceptions or gaps in prerequisite knowledge. The central feature is that assessment is embedded in the school's educational processes and is used to understand and support learning.
Formative assessment is an important component of school based assessment because it provides information during learning rather than only at the end. Teachers can use questioning, short written responses, retrieval activities, classroom discussion, observation and practice tasks to identify what pupils understand and where misconceptions remain. Effective formative assessment requires the evidence to influence subsequent teaching or learning.
If a teacher discovers that many pupils have misunderstood a concept, the information can lead to additional explanation, alternative examples, guided practice or another instructional approach. Individual learners can receive feedback that identifies what has been achieved and what needs further development. Formative assessment therefore functions as a feedback mechanism within instruction rather than merely as a series of tests.
Summative school based assessment provides evidence of attainment after a defined period of learning. Schools may use end of unit tests, examinations, coursework, projects, practical demonstrations or portfolios to determine whether learners have met specified objectives. Summative assessments can support reporting to pupils and families, internal progression decisions and, in some systems, formal qualifications. Their design needs to match the learning outcomes being assessed.
A test dominated by factual recall cannot adequately measure practical competence, while a purely practical task may not measure theoretical understanding. Schools therefore often use multiple assessment methods. The reliability and comparability of teacher judgements can also matter when grades are used for high stakes decisions, making moderation and shared criteria important.
Teacher assessment relies heavily on professional judgement. Teachers observe learners over time and can draw on evidence from many different activities rather than a single testing session. This can provide a richer picture of learning, particularly for practical, creative, collaborative or extended tasks. However, professional judgement can vary between assessors because expectations, interpretation of criteria and knowledge of learner performance may differ.
Schools can reduce some variation through common assessment criteria, standardisation exercises, moderation meetings, exemplars and review of marked work. Moderation involves comparing judgements and discussing evidence so that staff develop more consistent interpretations of standards. It does not eliminate judgement, because many educational outcomes cannot be reduced completely to mechanically scored items, but it can strengthen reliability and transparency.
School based assessment can also be diagnostic. Diagnostic assessment seeks to identify the nature of a learner's difficulty rather than merely assigning an overall score. In reading, for example, a teacher may investigate decoding, fluency, vocabulary and comprehension separately because a low overall reading score does not reveal which component requires intervention. In mathematics, errors can reveal misunderstandings about place value, fractions, algebraic relationships or procedural steps. Diagnostic information is useful when it changes teaching decisions. Assessment that merely identifies a problem without indicating what should happen next has limited practical value. Diagnostic assessment should also avoid overinterpreting individual errors because performance can be affected by task design, prior instruction and temporary factors.
School based assessment is closely connected to curriculum and pedagogy. Assessment should sample the knowledge and skills that the curriculum intends learners to develop, while teaching should prepare learners to understand and apply that content rather than merely predict particular test questions. If assessment systems reward narrow behaviours, they can influence what teachers spend time teaching. This is sometimes described as washback or backwash, meaning that assessment influences teaching and learning practices.
Positive alignment can encourage appropriate attention to important knowledge and skills, while poorly designed assessment can narrow the curriculum or encourage excessive teaching to the test. Schools therefore need to examine not only whether assessments are technically reliable but also whether their combined assessment programme supports the educational purposes of the curriculum.
Assessment information can be used at several levels within a school. Teachers can use it to adapt individual instruction, departments can identify curriculum areas requiring attention, senior leaders can examine patterns across cohorts and governing bodies or external authorities may use aggregated information for accountability. Data interpretation requires caution because attainment scores can be influenced by prior attainment, attendance, socioeconomic circumstances, language, special educational needs, curriculum changes and cohort composition.
A change in average performance does not automatically establish that teaching quality has changed. Schools can improve interpretation by combining quantitative assessment data with work scrutiny, observations, learner feedback and contextual information. Data are most useful when they lead to specific questions and actions rather than being treated as a substitute for professional reasoning.
The quality of school based assessment depends on validity, reliability, fairness, accessibility and appropriate use. Validity concerns whether the assessment provides suitable evidence for the intended interpretation, while reliability concerns consistency of measurement or judgement. Fairness requires consideration of whether assessment procedures disadvantage learners for reasons unrelated to the construct being assessed, and accessibility may require reasonable adjustments or alternative formats.
Assessment should also be proportionate because excessive testing consumes teaching time and can increase workload or anxiety without generating useful information. Effective school based assessment is therefore not simply a large quantity of testing. It is a coherent system in which teachers gather relevant evidence, interpret it carefully, provide meaningful feedback and use the information to improve learning and educational decision making.
