Discussions of explicit instruction versus various forms of implicit instruction are bedevilled by the problem that multiple factors often vary between the two models. I think that one such factor is critical to the success or failure of an instructional approach and it is a factor that is often not addressed.
It is worth going back to the teacher effects research (a good free summary can be found here). This research led to Barak Rosenshine developing his model of ‘direct instruction’ (which I call ‘explicit instruction’ for reasons outlined here), a key feature of which is that it is highly interactive. This is also a key characteristic of Direct Instruction as practiced in the DISTAR literacy and numeracy programs developed for Project Follow Through.
When we think of teacher-student interactivity, we tend to perceive it as a mechanism for gaining and giving feedback. However, it also serves another function; it promotes situational accountability. It is ‘situational’ in the sense that the accountability exists in the same learning episode as the instruction rather than after some delay. For instance, if there is a chance that you will be called upon to interact at some point in a lesson then you are more likely to pay attention to the instruction in that lesson. Situational accountability can be increased in a number of ways and to differing degrees. A simple approach might be to intersperse instruction with questions to randomly chosen students. However, it is also worth noting that Slavin’s two conditions for successful group work both act to increase situational accountability. So this is a more general idea.
I therefore think it might be worth viewing learning approaches along two axes; degree of explicitness and degree of situational accountability.
This model enables us to classify instructional practices into four broad sectors.
In the top right-hand corner we have explicit instruction as outlined by Rosenshine. It combines full guidance on new knowledge and procedures with a high degree of situational accountability. As a period of explicit instruction progresses, it will actually become less explicit as the instruction moves from modelled to guided and so it will move towards the vertical axis.
Lecturing needs to be placed in the bottom right-hand corner. There is little situational accountability in a large lecture. It is hard for the lecturer to know whether students are paying attention or not. This may not be a problem if the students have elected to be there due to interest. For instance, a student who is profoundly interested in, but knows little about, art history may gain a lot from a lecture because she will pay attention of her own accord. However, this might not be an effective approach for a mandatory catch-up algebra class designed for students who did not pass algebra at high school.
Interestingly, much of the research that is offered to support constructivism could be seen as comparing the bottom right-hand sector with the top right-hand sector. For instance, many studies in higher education seem to show a benefit of ‘active learning’ over ‘traditional lectures’. Active learning can be as simple as giving students clickers that allow them to vote on multiple choice questions presented during a lecture, thus slightly raising situational accountability.
In the bottom left-hand section we have self-determined inquiry. Although often promoted in schools, it is likely to be ineffective both because of the lack of explicitness and the lack of situational accountability. However, it is an appropriate approach for use by high prior knowledge individuals in the construction of new knowledge. Imagine a scientist testing the electrical properties of a newly created polymer: It would be both redundant and distracting to regularly ask the scientist questions about the approach and the theory behind it.
Finally, I have described the top left-hand portion as ‘accountable inquiry’. I am imagining forms of inquiry within certain constraints. There might be an objective to reach as in the solution of an open-ended maths problem. This does not preclude multiple pathways to the solution but it does enable accountability in the sense that progress towards the objective can be assessed. This kind of inquiry may take the form of being explicit about methods but not about the knowledge to be learnt. For instance, students might follow a set experimental or research procedure but they might be expected to draw their own conclusions from this. However, objectives and required behaviours will only produce situational accountability if the teacher is actively monitoring progress.
I suggest that all four broad forms of learning have their place.