Task 20

WORKSHEET

Materials and tools for a working group:

Concept Cartoons© – incline plane

The task is also focused on investigating of frictional force. The concept Cartoons© method is used. As with some of the previous tasks using this method, it is important to have enough time to justify claims using previous pupil experiences.

Pupils look at the picture and think about statements of three different persons thinking about the same situation differently. Their first task is to discuss in a group which of the statements they would agree with. Pupils should also be asked to justify their choice. Justification should be grounded in pupils´ previous experience, i. it may be an episode or some observed situation, according to which the pupils conclude that the chosen statement may be true one. In this part of the task, it is advisable to lead the pupils to agree on the group, but it is not necessary that there is certainty. The pursuit of compliance is to provoke sufficient justification for the selected statement by previous experience. However, students can enroll in individual predictions.

The teacher then moderates the class discussion. The aim is to agree on a solution through argumentation that is credible and convincing. Therefore, the teacher does not evaluate the opinions, only compares them and draws attention to differences of opinion and in particular to the differences in experience by which pupils support their claims. Naturally, a number of research questions will arise from the discussion. The image provides an incentive to use previous experience, making pupils‘ ideas ready for modification. This means that the picture itself does not have a clear solution, it should lead to the identification of what needs to be investigated. The statement that the pupils agree on as the most likely teacher formulates in a form of a research question and guides the pupils to propose the procedure as to whether it really is like that. For example, pupils may agree that a heavier object will move better, or a smoother object will move better; however, there is no problem if pupils also say a combination of both, for example, that a heavy and smooth object will move better (quicker).

Before pupils begin to proposeprocedures to verify their predictions, the teacher discusses what it means to move the object on an inclined board better. The term „better“ does not specify the variable to be examined. The task therefore leads pupils to always have a tendency to determine exactly what is going to be investigated. Pupils, for example, may agree that the better moving one is the object that gets from the top of the board to the bottom of the board the fastest. However, it is also interesting to find that it is easier to slip the object to which less force is needed to move up the board. While in the first case the pupils are looking for a procedure in which they objectively compare the speed of movement of the two objectson an inclined plate, in the second case they are looking for a procedure by which they can objectively compare the force that is required to pull the object up the board.

The most important part of the task (didactically the most valuable) is the discussion of what it means that the object is sliding on (off) the board „better“ and also the part of the activity in which pupils designed their own, sufficiently credible procedures, using they are able to verify predictions.

The teacher dedicates enough time for designing the procedures in groups and then the pupils present their proposals. In the discussion, it is important to focus in particular on whether it is actually possible to verify the predictions made (by finding out the answer to the research question). The teacher gradually learns pupils to look for potential shortcomings in the presented procedures, i. to approach objectively non-trusting proposals with a view to improving the process, or to jointly create one that everyone will understand and trust. The procedure whereby they agree and implement and conclude the examination. Since the implementation of the procedure is not a priority task of this assignment, it is possible to lead the pupils to carry out the procedure for the homework and at the next lesson, the teacher can only devote himself to the assessment, and can compare the same conclusions to the pupils in the individual verification. If not, the discussion can be extended to find out why the results were not the same. Inconsistent results are usually caused by other investigative conditions (i.e., failure to follow the original procedure, which must be described in such a way that each researcher can implement it in exactly the same way to obtain the same results).

Tasks 21–26 

Some of the identified research questions from the previous tasks be verified using procedures proposed in following tasks 21 to 26. If the pupils in the previous task have implemented the procedures they have designed themselves, the following tasks can be used to check the obtained results. All these tasks are aimed at exploring the frictional force of moving objects on an inclined plane.