Do we undermine formative assessment by confusing learning and performance?  Student performance during a lesson is “a highly imperfect index of long-term learning” (Soderstrom and Bjork, 2015), but it’s easy to assume that correct answers mean students have learned something – and will remember it.  Formative assessment relies on being able to elicit evidence of student achievement and adapt our teaching accordingly.  If we can’t rely on student answers in the lesson as evidence, does this undermine formative assessment?

Learning vs performance

Learning and performance are different:

  • Learning is a permanent change in behaviour or knowledge which supports retention and transfer.
  • Performance is a temporary fluctuation in behaviour and knowledge which can be observed and measured during and immediately after acquisition (Soderstrom and Bjork, 2015).

Measuring progress in lessons – students knowing more at the end than the beginning – means measuring a temporary fluctuation: it means measuring performance, not learning.

Strategies to increase performance can hinder learning; strategies that decrease performance can help students apply knowledge better and retain it longer.  One study asked children to throw beanbags at a target:

  • Group A threw from 3 feet
  • Group B threw from 2 and 4 feet
Image: Virginia State Parks

After a delay, both groups were tested throwing from 3 feet.  Even though Group A had practised from 3 feet, and Group B hadn’t, Group B did better: the variation in their practice made the initial task harder, but they learned more (Kerr and Booth, 1978 in Soderstrom and Bjork, 2015).

The same effect – worse performance, better learning – applies in the classroom.  Logic suggests students should complete several similar maths problems at once, for example, allowing them to gain confidence and facility in the calculation.  The principles of the beanbag study apply here too however; in one study, on finding the area of unusual shapes:

  • Group A studied four problems at a time for each shape
  • Group B studied sixteen problems in a random order

Group A performed far better during acquisition, but Group B learned more: one week later they answered three times more questions correctly than Group A (Rohrer and Taylor, 2007, in Brown et al., 2014).  Varying practice increases ‘germane cognitive load’: it forces students to think harder in ways which help them develop schemas more rapidly (Sweller et al., 1998).  There are a wide range of studies demonstrating this effect, reviewed by Soderstrom and Bjork (2015): what does this mean for assessment?

Formative assessment undermined?

David Didau has argued that the big idea of formative assessment is “fundamentally, and fatally, flawed”.  Didau suggests that, because performance in the lesson is no guarantee of learning, we cannot meaningfully adapt our teaching in response to evidence of student achievement.  He also claims that students are likely to be mimicking desired answers without knowledge (Didau and Rose, 2016)).  He and Nick Rose therefore conclude that:

Testing should not be used primarily to assess the efficacy of your teaching and students’ learning; it should be used as a powerful tool in your pedagogical armoury to help them learn (Didau and Rose, 2016: 102).”

Didau and Rose are right that testing is a powerful tool to help students learn – but this does not undermine formative assessment, for three reasons:

  1. Correct answers during lessons may not indicate what students will remember, but incorrect answers certainly indicate what students won’t remember correctly.  Formative assessment remains valuable, because we can identify student misconceptions in the moment, and adapt our teaching accordingly.  (Didau makes exactly this point, in the same blog post and a few sentences away from his declaration that formative assessment is entirely fatally flawed).
  2. No teacher would assume a correct answer from a student today means it will be remembered tomorrow.  Teachers do not need to have encountered Ebbinghaus’s forgetting curve to have experienced student forgetfulness.
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    We can assess what students have understood today without losing sight of the need to assess it again in future.  As Soderstrom and Bjork (2015) put it, we must:

Distinguish, in some way, between the relatively permanent changes in behavior and knowledge that characterize long-term learning and transfer and the momentary changes in performance that occur during the acquisition of such behavior and knowledge.”

This neatly introduces the third point:

3. Formative assessment allows us to do measure learning as well as performance.  Although Didau argues that formative assessment is “predicated on the assumption that you can assess what pupils have learned in an individual lesson”, this simply isn’t the case.  Within a lesson, we can get a sense of how much students have acquired; at the end of a week, unit or term, we can identify how much they have learned, and adapt our teaching accordingly.  We can test performance, we can test learning: in both cases we can adapt our teaching accordingly.


Didau’s arguments are a worthy reminder of the difference between learning and performance, but they do not undermine formative assessment.  If we assumed performance and learning were identical, formative assessment would be weakened – although not undermined.  But teachers are reminded every day that students forget things – even things they seemed to understand last lesson.  It’s important we distinguish between learning and performance and plan for learning.  It’s just as important that we assess how well our plans have worked and adapt our teaching accordingly: we cannot do without formative assessment.


Brown, P., Roediger, H., McDaniel, M. (2014) Make it Stick: The Science of Successful Learning. Belknap Press, Cambridge, MA.

Didau, D., Rose, N. (2016) What every teacher needs to know about… psychology. Woodbridge: John Catt.

Soderstrom, N., Bjork, R. (2015) Learning Versus Performance: An Integrative Review. Perspectives on Psychological Science, 10(2) 176–199.

Sweller, J., van Merriënboer J. J., Paas F. G. (1998). Cognitive architecture and instructional design. Educational Psychology Review, 10, 251-296.