A topic in teaching science
Scaffolding is a process of guiding a learner during a substantive learning experience.
(Read about 'Scaffolding Learning')
Circular motion is a topic where students often experience learning difficulties, and hold or develop alternative conceptions. Learning about circular motion usually builds upon prior learning of Newtonian physics applied in the case of linear motion. Students often develop alternative conceptions contrary to Newtonian physics. Even when the prerequisite knowledge has supposedly been learnt, learners may struggle to apply it in the context of circular motion.
A simple scaffolding device was designed and tested with A level students in England, and was found to support some learners in making sense of circular motion (Taber & Brock, 2018).
A simple task was designed to check prerequisite learning of students, and to help them bring to mind key relent principles that need to be applied to thinking about the circular motion to appreciate the scientific account. This kind of scaffolding tool has been called a 'scaffolding PLANK' – a device to help organise thinking to support new learning.
Then another simple task was provided to help students generate a logical chain of argument that would form the basis of an explanation of why a satellite moves in a circular, or near circular, orbit. This kind of scaffolding tool has been called 'scaffolding POLES' – a device to guide the structuring of new ways of thinking to support new learning.
(Read about 'Scaffolding tools')
Evaluation:
In a small-scale evaluation, using a convenience sample of classes, it was found (Taber & Brock, 2018) that
- approximately 30% of the students were unable to successfully complete the PLANK activity (which was intended to reflect prerequisite knowledge that would be assumed as prior learning in teaching the new topic – reflecting the conceptual difficulties students have with basic ideas in mechanics)
- of those that did successfully complete the PLANK activity, undertaking the POLES activity did increase the quality of student explanations of why a satellite moves in a circular orbit, indeed, on average, scores more than doubled
- but this was from a very low base, and reflected considerable improvements in some students, whilst the scaffolding task did not seem to support new learning in other learners.
Commentary
The evaluation represented an artificial activity. Teachers, kind enough the volunteer to help, administered an individual study activity that comprised of the PLANK task, explaining circular motion, the POLES task, and being asked to (again) explain circular motion (a similar number of students from the same classes followed a variation of the activity with the POLES task replaced by a superficially similar task unrelated to circular motion).
The finding that the scaffold of the POLES activity helped some students make progress, but not others, fits with the theory behind scaffolding, where a scaffold has to support learning in the student's so-called 'zone of proximal development' by balancing task challenge against a student's current state of knowledge and understanding through providing support that allows a challenging task to be tackled successfully. From this theory, we would not expect the same scaffolds to be effective for all students in a class.
(Read about the 'Zone of proximal development')
In an authentic teaching situation the materials would only be used when the teacher was ready to introduce the topic, and they would probably not be set as individual desk work.
A more authentic use would be:
- The teacher asks everyone to attempt the PLANK task – initially individually, but then to check their responses against those sitting around them.
- The teacher explains the nature of circular motion to the class.
- Student are asked to discuss the POLES activity in small groups, and to attempt to reach an agreed group solution (so that students have to explain and justify their ideas to each other). Those students who may not benefit from the activity working alone may be 'scaffolded' through working with a peer who is further along in her/his understanding .
That is, the task are intended to be integrated into normal class teacher, as tools to support the teacher's normal work as part of the repertoire that a teacher can call upon.
An invitation
Any teacher who thinks these tools may be useful in their teaching is welcome to download and use them. I would be very interested in any feedback on their usefulness with different classes.
Download the Scaffolding Circular Motion tools
Source cited:
Taber, K. S., & Brock, R. (2018). A study to explore the potential of designing teaching activities to scaffold learning: understanding circular motion. In M. Abend (Ed.), Effective Teaching and Learning: Perspectives, strategies and implementation (pp. 45-85). New York: Nova Science Publishers.
