Key ideas
Core concepts
- Formative assessment provides real-time data about student understanding, so teachers teach with their eyes open rather than closed.
- It reveals misconceptions during learning, before they become entrenched in schema, when correction is still cheap.
- It requires active data gathering, not self-report.
- Students are poor judges of their own understanding (the Dunning-Kruger effect).
Formative assessment means systematically assessing student understanding during lessons and using the results to inform and adjust teaching strategies in real time.
Connected to
Diagnostic Questions | Responsive Teaching | Mini-Whiteboards | Check for Understanding | Dunning-Kruger Effect | Schema | Misconceptions | Mathemagenic Activities | Implementation Fidelity
The problem without formative assessment
Without formative assessment, teachers have two inadequate options for understanding student learning. Student self-report (‘Do you understand?’) produces systematically invalid data due to the Dunning-Kruger Effect: students who most need help are least likely to recognise their confusion (Kruger & Dunning, 1999). Post-lesson tests and homework reveal problems only after misconceptions have become embedded in Schema, making correction far more difficult (Chi, 2008). Craig Barton (2018) compares teaching without formative assessment to painting with your eyes closed: you might eventually see the result, but by then it’s too late to adjust.
This creates a predictable pattern: teach, assign practice, discover widespread confusion during marking, reteach, repeat. Formative assessment breaks this pattern.
Principles of responsive teaching
Formative assessment improves student learning when teachers use the information to adjust instruction (Black & Wiliam, 1998). Meta-analyses show effect sizes ranging from 0.4 to 0.7 (Hattie & Timperley, 2007; Kingston & Nash, 2011).
Black and Wiliam (1998) identified five elements of effective formative assessment. First, clarify learning intentions and success criteria: students need to understand what they are learning and what success looks like, since clear goals focus effort and enable self-assessment. Second, elicit evidence of student understanding through questions, observations, and student responses during lessons; this evidence reveals actual understanding rather than assumptions. Third, provide feedback that moves learning forward, giving students specific information about how to improve rather than simply judging their work, with the focus on closing the gap between current and desired performance. Fourth, activate students as instructional resources for one another: peer assessment and collaborative work let students learn from each other, and explaining concepts to peers strengthens understanding for both. Fifth, activate students as owners of their own learning, developing self-regulation through self-assessment and reflection.
Responsive teaching requires three complementary elements. Participation must be universal: use Mini-Whiteboards and similar strategies that elicit responses from all learners, rather than relying on information from a few vocal students (Rosenshine, 2012). Assessment occurs frequently during lessons, not just at the end, so teachers catch problems before they compound (Wiliam & Thompson, 2007). And teachers interpret assessment data quickly, using tools like Diagnostic Questions to enable immediate instructional response (Black & Wiliam, 2009). Together, these create adaptive teaching where teachers slow down, reteach, or add scaffolding based on actual student understanding rather than curriculum expectations (Heritage, 2010).
Acting on the data during lessons
Effective formative assessment has two complementary components: gathering data and acting on it. Teachers can use Mini-Whiteboards for immediate visual feedback from all students, Diagnostic Questions to reveal specific misconceptions, observation of student work during independent practice for common errors, and exit tickets to inform next lesson planning. This data remains inert without an appropriate response.
Different success rates demand different actions (Rosenshine, 2012; Wilson et al., 2019). When more than 80 percent of students demonstrate success, continue with planned instruction as students are ready to progress. Success rates between 40 and 80 percent warrant peer explanation strategies like Turn and Talk, followed by re-assessment, as some students can effectively teach others. When success falls below 40 percent, stop and reteach using a different approach or different examples. When a common misconception emerges across multiple students, address it directly through cognitive conflict, exposing the logical contradiction in students’ thinking (Limón, 2001).
The data should drive teaching decisions rather than a fixed lesson plan (Wiliam, 2011).
Outcomes and limitations
Formative assessment generates benefits for both teachers and students. Teachers gain diagnostic data about student understanding (Heritage, 2010), identify topics requiring reteaching before progression (Black & Wiliam, 2009), and use findings to inform future lesson planning and curriculum pacing (Wiliam & Thompson, 2007), avoiding assumptions about what students have learned (Sadler, 1989). Students receive immediate feedback and correction (Hattie & Timperley, 2007), preventing misconceptions from becoming embedded in their schemas (Chi, 2008), and experience appropriate levels of challenge (Wilson et al., 2019). When coupled with a culture where errors are treated as learning opportunities, formative assessment supports risk-taking (Kapur, 2008).
Several pitfalls limit effectiveness. Relying on student self-report produces invalid data, as students cannot accurately judge their own understanding. Basing decisions on a vocal minority rather than representative data from all learners distorts instructional choices. Formative assessment without responsive action amounts to data collection without purpose. Quick fixes during lessons may address symptoms without targeting underlying conceptual gaps that require more substantial instructional change.
Practical examples
When Mini-Whiteboards reveal that 60 percent of students are adding fractions incorrectly, the appropriate response is to stop the planned lesson, address the misconception directly, and re-assess before moving forward. An exit ticket that shows students are confident despite making systematic errors signals a need to plan next lesson instruction specifically around that misconception rather than proceeding with planned content. When Diagnostic Questions during a worked example reveal gaps in prerequisite knowledge, teachers return to foundation concepts before continuing with new material rather than assuming students can catch up later.
References
Barton, C. (2018). How I wish I’d taught maths: Lessons learned from research, conversations with experts, and 12 years of mistakes. John Catt Educational.
Black, P., & Wiliam, D. (1998). Assessment and classroom learning. Assessment in Education: Principles, Policy & Practice, 5(1), 7-74. https://doi.org/10.1080/0969595980050102
Black, P., & Wiliam, D. (2009). Developing the theory of formative assessment. Educational Assessment, Evaluation and Accountability, 21(1), 5-31. https://doi.org/10.1007/s11092-008-9068-5
Chi, M. T. H. (2008). Three types of conceptual change: Belief revision, mental model transformation, and categorical shift. In S. Vosniadou (Ed.), International handbook of research on conceptual change (pp. 61-82). Routledge.
Hattie, J., & Timperley, H. (2007). The power of feedback. Review of Educational Research, 77(1), 81-112. https://doi.org/10.3102/003465430298487
Heritage, M. (2010). Formative assessment: Making it happen in the classroom. Corwin Press.
Kapur, M. (2008). Productive failure. Cognition and Instruction, 26(3), 379-424. https://doi.org/10.1080/07370000802212669
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
Kruger, J., & Dunning, D. (1999). Unskilled and unaware of it: How difficulties in recognizing one’s own incompetence lead to inflated self-assessments. Journal of Personality and Social Psychology, 77(6), 1121-1134. https://doi.org/10.1037/0022-3514.77.6.1121
Limón, M. (2001). On the cognitive conflict as an instructional strategy for conceptual change: A critical appraisal. Learning and Instruction, 11(4-5), 357-380. https://doi.org/10.1016/S0959-4752(00)00037-2
Rosenshine, B. (2012). Principles of instruction: Research-based strategies that all teachers should know. American Educator, 36(1), 12-19.
Sadler, D. R. (1989). Formative assessment and the design of instructional systems. Instructional Science, 18(2), 119-144. https://doi.org/10.1007/BF00117714
Wiliam, D. (2011). Embedded formative assessment. Solution Tree Press.
Wiliam, D., & Thompson, M. (2007). Integrating assessment with instruction: What will it take to make it work? In C. A. Dwyer (Ed.), The future of assessment: Shaping teaching and learning (pp. 53-82). Erlbaum.
Wilson, R. C., Shenhav, A., Straccia, M., & Cohen, J. D. (2019). The eighty five percent rule for optimal learning. Nature Communications, 10, 4646. https://doi.org/10.1038/s41467-019-12552-4