Formal vs Informal Assessment: A Practical Guide for Teachers
Formal and informal assessment are not competing philosophies. They describe how structured an assessment is. Diagnostic, formative, and summative describe why you are assessing. A teacher usually needs both dimensions.
That distinction fixes a common source of confusion. A five-question quiz could be an informal diagnostic check before a lesson, a formative check used to decide what to reteach, or a formal summative test recorded as a grade. The format alone does not tell you its purpose.
What is the difference between formal and informal assessment?
Formal assessment is planned, uses stated criteria, and produces a result that can be recorded or compared. Informal assessment is gathered through ordinary teaching, often with lighter documentation. Neither is automatically better.
| Dimension | Formal assessment | Informal assessment |
|---|---|---|
| Structure | Planned task with defined instructions and criteria | Observation or prompt embedded in normal teaching |
| Evidence | Usually recorded, scored, or retained | Often noted briefly or acted on in the moment |
| Examples | Rubric-scored essay, practical exam, unit test, standardized test | Listening to a group explanation, an exit question, a show of hands |
| Best use | Consistent judgments, reporting, certification, or comparison | Fast feedback about understanding, misconceptions, or participation |
| Main risk | A single result may be overinterpreted | Evidence may be inconsistent or poorly documented |
An assessment's formality does not determine whether it is diagnostic, formative, or summative. Purpose does.
What are diagnostic, formative, and summative assessments?
Diagnostic assessment establishes a starting point, formative assessment informs the next step during learning, and summative assessment supports a judgment after a period of learning.
Diagnostic assessment: what do students know before instruction?
Use a diagnostic assessment before a course, unit, or difficult concept. The aim is not to award a grade. It is to find prerequisite gaps and misconceptions that should change the plan.
Useful options include a short pre-quiz, a concept map, two open-response questions, or a confidence check paired with questions that test actual knowledge. Carnegie Mellon University's Eberly Center distinguishes direct measures such as tests and concept maps from indirect measures such as self-reports. It also warns that students may not estimate their own ability accurately, so a confidence survey should not be your only evidence (Carnegie Mellon University, n.d.).
Prior knowledge matters, but not in the simple way the old slogan "knowledge is power" suggests. A meta-analysis of 8,776 effect sizes found that prior knowledge strongly predicted knowledge at post-test, while its relationship with how much new knowledge students gained varied widely across studies (Simonsmeier et al., 2021). That is a reason to diagnose the starting point, not to assume that students who begin ahead will always learn faster.
Formative assessment: what should happen next?
Formative assessment is a feedback process during learning. Evidence becomes formative when a teacher or student uses it to adjust what happens next. The US Department of Education describes this as using assessment evidence to change current teaching or learning, for example by reteaching a concept, changing the explanation, or adding practice (US Department of Education, n.d.).
Examples include an exit ticket that determines tomorrow's starter, a low-stakes quiz followed by targeted practice, or comments on a draft that a student uses in a revision. A quiz that is collected and ignored is not meaningfully formative.
There is evidence that formative assessment can improve achievement, but the size of the effect is not settled. Kingston and Nash (2011) found a weighted mean effect of 0.20 across 13 usable K-12 studies, after excluding many studies with designs that did not support a clear inference. Briggs et al. (2012) then challenged parts of that meta-analysis's methodology. The sensible conclusion is modest: formative assessment can help, but its value depends on the quality of the task, feedback, and instructional response. It is not a guaranteed result of giving more quizzes.
Summative assessment: what have students achieved?
Summative assessment supports a judgment after a defined period of learning. Examples include a final project, end-of-unit test, practical demonstration, or dissertation. These assessments are often formal and graded, but "summative" refers to their purpose, not a required format.
Summative evidence is useful for reporting attainment or deciding whether a standard has been met. It arrives too late to repair the learning sequence it measures, so it should not be the teacher's only source of information. The OECD treats formative and summative assessment as connected parts of an assessment system, with different uses for the evidence each produces (OECD, 2025).
Which assessment type should you choose?
Start with the decision you need to make. Then choose the least burdensome method that gives you credible evidence for that decision.
| Decision | Suitable assessment | What to do with the result |
|---|---|---|
| Can students use the prerequisite concept? | Diagnostic pre-quiz with one misconception probe | Reteach the prerequisite or provide targeted support |
| Is today's explanation working? | Informal questioning or an exit ticket | Change the next explanation, grouping, or practice task |
| Can students apply the skill independently? | Formal task scored with a rubric | Give actionable feedback and plan another attempt if appropriate |
| Has the unit standard been met? | Summative test, project, or practical | Record the judgment and review patterns before the next unit |
Do not collect evidence without deciding how it will be used. A stack of weekly quiz scores is not a formative system unless somebody changes course because of them.
How can you assess prior knowledge without wasting class time?
Use a short diagnostic cycle:
- Name the prerequisite knowledge. Write down the two or three ideas students need before the new lesson.
- Ask for evidence, not recognition alone. Include a short explanation or application question alongside multiple-choice items.
- Include one plausible misconception. A wrong answer is more useful when it reveals a specific misunderstanding.
- Look for class-level patterns. One student's error may need individual support; the same error across half the class calls for a change to instruction.
- Respond visibly. Tell students what the check changed: "Most of us can identify the parts of a cell, but we need ten minutes on membrane transport before moving on."
Cornell's Center for Teaching Innovation suggests short true-or-false misconception checks, multiple-choice questions, or two to three open questions at the start of a course or unit (Cornell University, n.d.). The important step is the response. If the result does not affect teaching, the diagnostic has become paperwork.
Does informal assessment solve test anxiety?
No. Lower-stakes, familiar checks may feel less threatening for some students, but "informal" does not mean anxiety-free, and it does not make the evidence automatically fairer or more accurate.
A 30-year meta-analysis covering 238 studies found that test anxiety had small-to-moderate negative relationships with several performance outcomes, including standardized tests, entrance exams, and grade point average (von der Embse et al., 2018). That is an association across varied studies, not proof that a particular formal assessment caused a particular student's result.
Use proportionate stakes, clear criteria, accessible instructions, and more than one relevant observation when the decision warrants it. Follow your institution's accommodation and assessment policies. Do not discard necessary formal assessment solely because an informal alternative feels friendlier.
How can teachers build a balanced assessment plan?
For one unit, plan four moments:
- Begin with a brief diagnostic check of prerequisites.
- Use one or two informal formative checks while teaching.
- Give students a formal practice task with criteria and time to respond to feedback.
- Finish with a summative task aligned to the same learning objective.
Suppose the objective is to explain how photosynthesis transfers energy. A diagnostic prompt could ask students where a plant's mass comes from. During the unit, an exit ticket could expose confusion between matter and energy. Students could then revise a labelled explanation using a rubric before completing the final task. The assessments differ in formality and purpose, but they work as one sequence.
If you already have a syllabus, reading, or slide deck, Quizgecko's quiz generator can turn that source material into draft questions. Teachers can also create a quiz from a PDF, build a broader set of activities with the AI study guide maker, or review Quizgecko's tools for schools and teachers. AI-generated questions still need human review for factual accuracy, wording, accessibility, difficulty, and alignment with the intended decision.
The practical answer to "formal or informal?" is usually both. Use informal evidence to notice and respond quickly. Use formal evidence when consistency and documentation matter. Use diagnostic, formative, and summative labels to keep the purpose clear.
References
Briggs, D. C., Ruiz-Primo, M. A., Furtak, E. M., Shepard, L. A., & Yin, Y. (2012). Meta-analytic methodology and inferences about the efficacy of formative assessment. Educational Measurement: Issues and Practice, 31(4), 13-17. https://doi.org/10.1111/j.1745-3992.2012.00251.x
Kingston, N., & Nash, B. (2011). Formative assessment: A meta-analysis and a call for research. Educational Measurement: Issues and Practice, 30(4), 28-37. https://doi.org/10.1111/j.1745-3992.2011.00220.x
Simonsmeier, B. A., Flaig, M., Deiglmayr, A., Schalk, L., & Schneider, M. (2021). Domain-specific prior knowledge and learning: A meta-analysis. Educational Psychologist, 57(1), 31-54. https://doi.org/10.1080/00461520.2021.1939700
von der Embse, N. P., Jester, D., Roy, D., & Post, J. (2018). Test anxiety effects, predictors, and correlates: A 30-year meta-analytic review. Journal of Affective Disorders, 227, 483-493. https://doi.org/10.1016/j.jad.2017.11.048
