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Learning News Week 9 Term 3

Year 4 visit the Year 8 science classroom to check out their experiment.

From Alpha Thinking to Beta Thinking to Beta Sentences

Spherical ice moulds are very nifty gadgets. Fill them up to 8/9 of the total volume and place in the freezer for a day and voilà! The water expands into the full sphere as it freezes and with the mould removed, a near perfect ice ball is formed. The ice balls make for an attractive ice block in your favourite fizzy drink or for the more playful mind, a slowly melting sphere ideal to race down “hot wheel” tracks.

These orange tracks are toys from the 1970’s specifically designed for the fast tiny wheeled cars that can be released from a high starting position to zoom down to a low flat straight. Now what do you race against an ice ball down a hot wheels track? Why a golf ball of course! Another sphere but with dimples. Which ball should win and why?

This was a part of the Year 8 Science EEI assessment for my class for the past two weeks. And their enthusiasm was infectious. The students had numerous races and on average the ice ball won against the golf ball. Then the difficult part started. How to interpret this, perhaps understand this and even explain it back in words, and the real challenge, which was to do so in writing.

Energy is the theme for this term. Given the study of Physics is the study of energy, these spheres racing down tracks fitted well. The class had learnt the terms kinetic energy, gravitational potential energy, as well as friction force from their Year 7 science classes. But during the races, these terms were never mentioned, with the exception of friction which was used as the general excuse for unexpected results. The pre-race favourite was the golf ball with its slick lines, dimpled face and an iconic Dunlop badge. So when the ice ball slid past the finishing line narrowly ahead of the golf ball, an appreciation of sliding versus rolling developed. The class thinking was essentially intuitive, hence Alpha thinking. Alpha thinking is the easy, light hearted, intuitive thinking associated with being entertained.

Our class eventually returned to their places, opened their science books and obediently started copying diagrams of small hills, slopes and extended flats. GPE was labelled on the hill section and KE on the flats. GPE for Gravitational Potential energy and KE for Kinetic Energy. Golf balls were drawn with circles around the outside to indicate that the golf ball commonly rolls. The first awkward discussion question: why does the golf ball roll down the slope yet the ice ball slides? This needs Beta thinking because the students are required to introduce the idea of friction more precisely. Where was the friction important? At the bottom of the ball of course, slowing that part down whole the top part rolled past it and then the next part of the ball was slowed. Yes, the class nodded, proud of their beta thinking. So the ice ball does not do this, because the melting water at the bottom of the ball removes most of this friction so the top does not roll over the bottom. The energy trail completes the story. The golf ball now has rolling kinetic energy and moving forward kinetic energy. The ice ball however has only moving forward kinetic energy, giving it slightly greater speed and victory on most occasions.

Once the diagrams, arrows and symbols were completed, some students were asked to explain this all to the class. More Beta thinking, as they now had to sequence their ideas and grab enough words to release thirty-five seconds of nervous energy in front of their class. This was generally successful if the teacher is trained in the Aussie student dialect and with precise timing can add a few helpful terms. Homework for that night was to “Write a paragraph with Beta sentences discussing the experiment”. Beta sentences are a serious threat to Year 8 students as these sentences need to explain each idea carefully and then link to the next sentence.

In marking the homework it showed that it is quite a challenge for boys to write in Beta sentences. They know what a sentence looks like, but sense they are too busy completing the task to add full stops and capital letters. The step from a reasonably successful oral explanation to a series of scientifically written linked sentences is challenging for Year 8 boys. Amongst ATC teachers this is now recognised as the most important academic goal for our learners. If teachers and students are successful in improving this situation, then students will make significant progress across a range of their subjects. We are quietly confident in achieving this before others may even recognise that this is an Australia-wide problem in our schools.

Mr Greg Quinn, Assistant Dean of Learning
quinng@atc.qld.edu.au