I AGREE with Ms Ashley Chan Kway Lan that science should encourage inquisitiveness ("Science shouldn't have 'model' answers"; last Saturday). Having to rigidly abide by key words in tests somehow moves in the opposite direction.
Key words do serve a purpose but should be taken only as a guideline ("Focus on understanding, not key words, in science" by Ms Elizabeth Tan Boon Kwan; Monday, "'Key words' are key to how kids learn science" by Mr Lai Tuck Chong; Tuesday, "Spark interest first, key-word proficiency will follow" by Mr Chee Chin Young; Wednesday, "Science a test of language instead?" by Dr Inez Perera; Forum Online, Wednesday, and "Good science = Poor English?" by Mr Edwin Lee Peng Khoon; Forum Online, yesterday).
One day, I switched roles with students and asked them to evaluate my answer to a question: "Some water was spilled onto a digital balance. Why did the reading of the balance decrease a while later?"
My trial answer was, "Water disappeared". While some students endorsed my answer, others disagreed. I managed to convince the students that my explanation was not incorrect because water has mass and when the mass disappeared from the balance, the reading decreased.
Then I presented my preferred answer, "Water evaporated". All acknowledged that it was a better answer but could not quite explain why. I elaborated, "The word 'evaporated' demonstrates a deeper understanding of the phenomenon because it indicates not only the process that water has undergone to change its state, but also the disappearance of mass."
The students responded with nodding heads.
"Some of you may wonder why teachers emphasise answer keys. Through this example, I hope you recognise that answer keys serve as a guideline to indicate the depth of understanding required rather than having to memorise them merely for examination purposes," I added. They responded with smiling faces.
I did have some negative experiences with key words. Last year, a parent sought my help to assess her primary school daughter's science answers.
One question was about why elephants spray water on their bodies on hot days. The pupil wrote, "As water gains heat from elephants and turns into water vapour, the elephants feel cooler."
It was not about half of the marks allocated being taken away, but more of the fact that although the pupil had demonstrated a clear understanding of the underlying concept, she was penalised for stating the key word "evaporates" in another acceptable way, "turns into water vapour".
In conclusion, key words should serve as a guideline to indicate the depth of understanding required but not as "model" answers.
Tan Kah Chye (Dr)
Key words do serve a purpose but should be taken only as a guideline ("Focus on understanding, not key words, in science" by Ms Elizabeth Tan Boon Kwan; Monday, "'Key words' are key to how kids learn science" by Mr Lai Tuck Chong; Tuesday, "Spark interest first, key-word proficiency will follow" by Mr Chee Chin Young; Wednesday, "Science a test of language instead?" by Dr Inez Perera; Forum Online, Wednesday, and "Good science = Poor English?" by Mr Edwin Lee Peng Khoon; Forum Online, yesterday).
One day, I switched roles with students and asked them to evaluate my answer to a question: "Some water was spilled onto a digital balance. Why did the reading of the balance decrease a while later?"
My trial answer was, "Water disappeared". While some students endorsed my answer, others disagreed. I managed to convince the students that my explanation was not incorrect because water has mass and when the mass disappeared from the balance, the reading decreased.
Then I presented my preferred answer, "Water evaporated". All acknowledged that it was a better answer but could not quite explain why. I elaborated, "The word 'evaporated' demonstrates a deeper understanding of the phenomenon because it indicates not only the process that water has undergone to change its state, but also the disappearance of mass."
The students responded with nodding heads.
"Some of you may wonder why teachers emphasise answer keys. Through this example, I hope you recognise that answer keys serve as a guideline to indicate the depth of understanding required rather than having to memorise them merely for examination purposes," I added. They responded with smiling faces.
I did have some negative experiences with key words. Last year, a parent sought my help to assess her primary school daughter's science answers.
One question was about why elephants spray water on their bodies on hot days. The pupil wrote, "As water gains heat from elephants and turns into water vapour, the elephants feel cooler."
It was not about half of the marks allocated being taken away, but more of the fact that although the pupil had demonstrated a clear understanding of the underlying concept, she was penalised for stating the key word "evaporates" in another acceptable way, "turns into water vapour".
In conclusion, key words should serve as a guideline to indicate the depth of understanding required but not as "model" answers.
Tan Kah Chye (Dr)
