The failure of ‘pure discovery’ learning:
The case against ‘pure’ discovery learning is pretty damning. A number of fairly recent papers have consistently reported that minimally guided instruction simply doesn’t work.
It’s interesting to note that doubts about the efficacy of the approach are not particularly new. Even Bruner (quoted by Tuovinen, here) appeared to hold the view that discovery learning would only play a small role in education.
Although Bruner championed the discovery learning cause, he argued that existing knowledge and culture were not generally passed on by discovery. He wrote (1966, p. 101):
“You cannot consider education without taking into account how culture gets passed on. It seems to me highly unlikely that given the centrality of culture in man’s adaptation to his environment – the fact that culture serves him in the same way as changes in morphology served earlier in the evolutionary scale – that, biologically speaking, one would expect each organism to rediscover the totality of its culture – this would seem most unlikely. Moreover, it seems equally unlikely, given the nature of man’s dependency as a creature, that this long period of dependency characteristic of our species was designed entirely for the most inefficient technique possible for regaining what has been gathered over a long period of time, i.e. discovery.”
Keeping an open mind on ‘enhanced discovery’ learning:
On the other hand there’s some evidence to suggest that when discovery learning is highly scaffolded, then the negative effects are mitigated …
… and even some evidence that it can outperform direct instruction in some circumstances.
Alfieri et al – Educational Psychology, 2011
Robert Marzano suggests that:
“When faced with the decision whether to use direct instruction or unassisted discovery learning, a teacher should opt for the former. However, if a teacher is willing to put time and energy into designing lessons that ensure that students have the knowledge needed to understand the content and that provide guidance and interaction along the way, then discovery learning can be a powerful learning experience for students.”
Tuovinen makes the point that some versions of discovery learning involve a significant amount of direct instruction and incremental structure.
“One conclusion that can be drawn is that instead of a clear dichotomy between, say, deductive discovery and deductive reception learning, we have a continuum where the methods of teaching and learning differ by gradually varying amounts of guidance, direction, structure, help, learner control, and other dimensions, rather than being neat separate categories.”
Looking through Tuovinen’s taxonomy there are hints as to the processes which determine the success or failure of an instructional technique. I won’t list them here, instead I want to explore some of the possible reasons why ‘pure’ discovery learning fails and explore why direct instruction and some of the more structured forms of discovery learning tend to succeed.
Why does pure discovery learning fail?
Induction is harder than deduction – one possibility is that discovery learning simply overloads our students’ ability to successfully process and encode the material to be learnt. One reason for this might be that inductive reasoning (synthesising a general rule from a number of specific instances) is enormously complex – requiring the student to correctly attend to the pertinent information in each specific instance (as opposed to all the extraneous information) and hold them all ‘in mind’ long enough to discern the general pattern of behaviour. Deductive reasoning (using specific instances to test a general rule) requires less mental juggling. Testing a hypothesis involves holding a rule in mind and comparing it to a specific case to see if the rule holds.
On the other hand, we remember what we think about, so as long as the inductive jumps are fairly small the additional processing required may assist the learning process. It might be difficult to judge the appropriate amount of element interactivity for a group of students, but the additional challenge it provides might be advantageous in some circumstances.
Subject knowledge – a mediating factor appears to be the extent to which students possess background knowledge which can assist them with processing the new information. We know that our prior knowledge about a topic plays an active role in helping us process new information. Where prior knowledge is poor, working memory is swamped and very little appears to be successfully learnt.
However, there’s some evidence from Tuovinen and Sweller -Educational Psychology (1999) that where domain knowledge is pretty good, then the choice of instructional technique has little influence on outcomes.
“However, if students had previous familiarity with the database domain, the type of practice made no significant difference to their learning because the exploration students were able to draw on existing, well-developed domain schemas to guide their exploration.”
Kirschner et al also note that:
“The advantage of guidance begins to recede only when learners have sufficiently high prior knowledge to provide “internal” guidance”
… which implies that where students have a pretty firm foundation in a topic (e.g. following direct instruction) there may be advantages to using a structured discovery technique as a way of getting students to apply that knowledge.
Along with subject knowledge, the conceptual difficulty of the learning is also likely to be a factor. Typically, direct instruction of an abstract concept may be preferable because it may not be easily observable (and therefore discoverable) – but there are exceptions (e.g. density is a tricky concept for many students, but easy to investigate using displacement).
Group size – another possibility for the failure of pure discovery is the phenomenon of social loafing. This is the finding that as the number of people in a group increases; their individual efforts tend to decrease. Most discovery learning methods involve high levels of student collaboration and a mediating factor might simply be that average effort expended on the task is lower than when working individually.
On the other hand, there’s some evidence from the EEF that collaborative activities can produce significant learning gains – but the devil is in the detail of how the group activity is structured.
“The impact of collaborative approaches on learning is consistently positive, but it does vary so it is important to get the detail right. Effective collaborative learning requires much more than just sitting pupils together and asking them to work together; structured approaches, with well-designed tasks lead to the greatest learning gains.”
Unnecessary focus on biological primary skills – Geary describes biologically primary learning as abilities and knowledge which arise innately, are learnt rapidly and don’t need to be taught. Much of the modern emphasis on skill-over-knowledge tends to highlight the importance of students practicing these sorts of skills. For example, Guy Claxton’s BLP framework encourages teachers to highlight the development of various learning dispositions, for example, imagining, imitation and noticing. It seems likely that these traits don’t need or improve with practice and may even provide a distraction from the biological secondary knowledge and skills that would.
However, there are some learning skills which may benefit from explicit focus. Again, the EEF reports that meta-cognitive and self-regulation strategies can produce strong gains for some students (mainly lower achieving and older students).
“The potential impact of approaches which encourage learners to plan, monitor and evaluate their learning is very high. However it can be difficult to achieve these gains as this involves pupils in taking greater responsibility for their learning and in developing their understanding of what is involved in being successful. There is no simple strategy or trick for this. It is possible to support pupils’ work too much, so that they do not learn to monitor and manage their own learning but come to rely on the prompts and support from the teacher. A useful metaphor is scaffolding in terms of removing the support and dismantling the scaffolding to check that learners are taking responsibility to manage their own learning.”
Learner control – a further issue for discovery learning is that students are directing their own studies rather than following the guidance of a subject expert. Though the teacher may carefully select materials to support the formation an accurate understanding of a topic, students may simply confirm their misconceptions and ignore disconfirming evidence available to them. This factor will likely correlate to the prior knowledge of the students and Tuovinen notes that even ‘progressive’ teachers tend to avoid a genuinely ‘pure’ discovery approach:
“Wittrock (1966) found that many of the discovery learning approaches discussed in the literature actually consisted of a conventional ‘lesson plus practice’ (expository) teaching approach, which approximated to the deductive discovery learning approach, with varying amounts of direction provided during the practice (discovery) stage.”
On the other hand, along with a sense of mastery and purpose, having a sense of personal autonomy is an important element of our intrinsic motivation. Self-determination theory suggests that being able to provide students with elements of choice – obviously within a structured learning environment – may have a positive influence on student performance through improving their self-efficacy.
Behaviour management – There’s certainly evidence that poor behaviour affects student academic performance and the 10 year study by Hayden shows that deficits in classroom climate are not uncommon in English schools. Another mediating factor behind the failure of discovery learning might be the opportunities presented by more flexible learning environments for students to simply not focus on what they are learning. Discovery learning activities typically involves a great deal of student movement and interaction and this tends to raise noise levels and affords potential misbehaviour.
However, many teachers use discovery learning techniques precisely because they believe the elements of choice, peer-interaction, etc improve student motivation and thereby reduce behaviour problems. Whilst there’s plenty of qualitative commentary suggesting this correlation, I’m not aware of any quantitative evidence to support or refute the claim. It would be interesting to see an RCT – perhaps using Haydn’s 1-10 rating scale of classroom climate – comparing enhanced discovery learning and direct instruction. My intuition is that the outcomes would be broadly comparable (i.e. instructional style will not account for much variance in student behaviour) – but I don’t know.
There’s good evidence to suggest that ‘pure’ discovery learning is an ineffective way for students to learn and direct instruction appears always to lead to better outcomes. However, there are interesting lessons to be learnt by examining why minimally guided instruction fails.
There’s also evidence on more structured forms of discovery learning which is far from damning and in some cases suggests it can even outperform direct instruction. It is likely that a variety of complex and interacting factors (of which I’ve only listed a few) influence the relative success or failure of an instructional technique, but there’s some interesting psychology behind why both direct instruction and guided discovery methods might be appropriate depending on the circumstances.