Assessment is the systematic process of gathering, interpreting and using evidence about a person's knowledge, understanding, skills, abilities, performance or progress in relation to defined criteria, learning outcomes or standards. In education, assessment is used to determine what learners know and can do, identify learning needs, provide feedback, support instructional decisions and, in some circumstances, make formal decisions about progression or certification.
Assessment can take many forms, including examinations, essays, projects, presentations, practical demonstrations, portfolios, observations, oral examinations and computer based tasks. It is broader than simply assigning marks because assessment includes the design of evidence collection, interpretation of performance and use of results. A sound assessment process therefore requires a clear relationship between what students are expected to learn, what evidence is collected and how that evidence is judged.
Educational assessment is commonly divided into formative and summative assessment according to its primary purpose. Formative assessment is conducted during learning to generate information that can be used to improve teaching and learning before a final judgement is made. It can include questioning, draft work, classroom tasks, feedback and low stakes quizzes. Summative assessment is generally used to evaluate achievement at the end of a unit, course or defined period and may contribute to grades or qualifications.
The distinction concerns purpose rather than a rigid format because the same assessment activity can sometimes serve both functions. Diagnostic assessment is another important category and is used to identify existing knowledge, misconceptions, strengths or learning needs before or during instruction. Effective assessment systems often combine several purposes rather than relying on a single test.
Assessment can also be classified according to how performance is interpreted. Criterion referenced assessment judges a learner's performance against predefined criteria or standards rather than against the performance of other learners. Norm referenced assessment interprets performance in relation to the distribution of scores within a defined comparison group. Ipsative approaches compare current performance with a learner's previous performance and can be useful for monitoring individual development.
Authentic assessment attempts to evaluate the application of knowledge and skills in tasks resembling meaningful real world activities, while performance assessment requires learners to demonstrate a skill or process rather than merely select an answer. These categories can overlap, and the appropriate method depends on the learning outcomes and decisions that assessment results are intended to support.
Validity and reliability are fundamental technical concepts in assessment. Validity concerns the extent to which the interpretations and uses made from assessment evidence are supported by appropriate evidence and reasoning. It is not simply a property of a test in isolation because the same assessment may be appropriate for one purpose and inappropriate for another.
Important considerations include whether the assessment adequately represents the intended content, whether the cognitive processes being measured are appropriate and whether external factors distort the interpretation. Reliability concerns the consistency or dependability of measurement under relevant conditions. Sources of inconsistency can include ambiguous questions, inconsistent marking, sampling variation and unstable testing conditions. Good assessment design seeks sufficient reliability while preserving meaningful measurement of the intended learning.
Assessment quality also depends on fairness and accessibility. An assessment can unintentionally disadvantage learners when performance depends on factors unrelated to the intended learning outcomes, such as inaccessible materials, unnecessary language complexity, inappropriate timing or unfamiliar technology. Reasonable adjustments may therefore be necessary for disabled learners, while accessible design can benefit a wider population.
Fairness does not necessarily mean giving every learner exactly identical conditions because legitimate adjustments may be required to remove barriers that are irrelevant to the construct being assessed. Bias can also arise through cultural assumptions, poorly designed contexts or differential familiarity with assessment conventions. Assessment systems should therefore consider whether observed differences in performance genuinely reflect differences in the knowledge or skills that the assessment is intended to measure.
Assessment serves several functions within educational systems. At classroom level, teachers use assessment evidence to adapt instruction, identify misconceptions and determine whether students are ready for more advanced material. At institutional level, assessment contributes to progression decisions, programme evaluation and quality assurance. At national or system level, standardised assessments can provide information about educational attainment and enable comparisons across schools or regions. In professional education, assessment can determine whether learners have reached competencies required for practice. In qualifications, assessment provides evidence that a candidate has met specified learning outcomes. These functions create different design requirements. A low stakes classroom quiz can be useful for immediate feedback without needing the same security procedures as a high stakes professional examination.
Marking and grading are related to assessment but are not synonymous with it. Marking involves applying criteria or rules to assign marks or judgements to particular pieces of evidence. Grading converts or summarises performance into categories such as letter grades, classifications or achievement levels. Moderation can be used to improve consistency between markers or assessors by reviewing standards and judgements. Standard setting may be used to determine performance thresholds for qualifications or competency decisions.
Feedback is another important component, particularly when assessment is intended to support learning. Effective feedback should provide useful information about current performance and possible improvements rather than merely reporting a numerical result. Excessive reliance on grades can sometimes reduce attention to the formative information that assessment can provide.
Assessment has limitations and potential unintended effects. A single examination provides only a sample of a learner's performance and can be influenced by anxiety, health, familiarity with the format, language proficiency and other contextual factors. High stakes assessment can influence teaching and learning because institutions and teachers may concentrate on material that is likely to appear in examinations. Poorly aligned assessment can encourage memorisation when the intended learning requires analysis, creativity or practical competence. Conversely, carefully designed assessment can promote deeper learning by requiring students to apply, explain, evaluate and create. Digital assessment introduces additional possibilities such as automated feedback and adaptive testing but also raises issues concerning accessibility, data protection, technical reliability and academic integrity.
