Q&A - PSLE Science

[Ler]

tianzhu:

P5G:

The correct link is as follows:


http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-StNic.pdf

Worksheet answer is (1).

My answer is (4).

Please advise which is correct.

Hi P5G

The experiment seeks to compare the amount of water in four vegetables.

Therefore, one is required to examine (two or more objects) in order to observe or discover similarities or differences.

The initial weight minus the final weight is the weight of water. This difference multiplied by 100 and divided by the initial weight will give you the percent water content.

For (A) we are comparing vegetables with the same weight as compared to different quantities in the other options.

Best wishes

Hi All


Any KSP parent from nanyang primary, Could you mind to share nanyang science solution for SA2-2010 of primary 6 , paper 2 fm question 31 to question 44. The answer provided by Jeremy seems to be wrong, can anybody highlight it or provided school solution on this forum.

Thanks

Ler

[tianzhu]

Ler:

Any KSP parent from nanyang primary, Could you mind to share nanyang science solution for SA2-2010 of primary 6 , paper 2 fm question 31 to question 44. The answer provided by Jeremy seems to be wrong, can anybody highlight it or provided school solution on this forum.

Hi Ler

Good Morning

You made a post @02:59 , which only means you are working very hard to help your PSLE kid.

By limiting yourself to KSP parents from NYPS, you are narrowing your circle of exposure.

I suggest you post the questions, tell us why you think the answers provided in the WS are wrong.

KSP has high traffic and you may some answers to your questions, but first you must post the questions.

Best wishes

[tianzhu]

naggo-nitemare:

Qn 15: Answer should be (2). \"Flower is beautiful\" is not a Science concept. \"Anther is shorter than stigma\" is to prevent cross pollination

Qn 17: Answer should be (2). Longer rubber band will make it travel shorter distance. Bigger plastic roller has bigger circumference so it can travel further.

Qn 18: Answer should be (2)

Qn 21: Answer should be (2). If S1 and S2 are closed, short circuit will occur.

Hi Ler

Please refer to this link for some of NYPS Science MCQ answers.
http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6459&start=350

Best wishes

[Ler]

tianzhu:

naggo-nitemare:

Qn 15: Answer should be (2). \"Flower is beautiful\" is not a Science concept. \"Anther is shorter than stigma\" is to prevent cross pollination

Qn 17: Answer should be (2). Longer rubber band will make it travel shorter distance. Bigger plastic roller has bigger circumference so it can travel further.

Qn 18: Answer should be (2)

Qn 21: Answer should be (2). If S1 and S2 are closed, short circuit will occur.

Hi Ler

Please refer to this link for some of NYPS Science MCQ answers.
http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6459&start=350

Best wishes

Thanks,

[atutor2001]

Hi everybody


One of my friends asked me why is it necessary to "repeat an experiment". Without thinking I regurgitated : "so that the results will be more reliable, consistent and accurate".

She told me that her DD’s teacher told them that "accurate" cannot be used. Another friend also said the same thing. Just curious, is this the latest MOE teaching concept.

I used to teach my kids that "repeating an experiment" will make results more accurate because it allows the "average" to be computed, which will help to reduce experimental error. Wonder why it is no longer valid. Hope to hear your comments. Thank you.

[rkumar]

atutor2001:

Hi everybody


One of my friends asked me why is it necessary to \"repeat an experiment\". Without thinking I regurgitated : \"so that the results will be more reliable, consistent and accurate\".

She told me that her DD's teacher told them that \"accurate\" cannot be used. Another friend also said the same thing. Just curious, is this the latest MOE teaching concept.

I used to teach my kids that \"repeating an experiment\" will make results more accurate because it allows the \"average\" to be computed, which will help to reduce experimental error. Wonder why it is no longer valid. Hope to hear your comments. Thank you.

Hi atutor,

I believe the teacher might be right. Repeating the steps in the same experiment would give you a better \"average\". But average is by no means referring to accurate. The reason you would average a series of data means that none of the data can be determined to be accurate. If it any of the data was accurate you would not need to average them(hope you understand what i mean).

Also \"repeating the steps\" is not the same as \"repeat an experiment\". You are in fact repeating the whole experiment to find out if the 2nd results are consistent(as you said) with the 1st.

I am also surprised that the teacher had told the class not to use the word.
Can anyone else verify MOE stand on this?

[atutor2001]

Hi rkumar


Thank you for your view.

[Dharma]

atutor2001:

Hi everybody


One of my friends asked me why is it necessary to \"repeat an experiment\". Without thinking I regurgitated : \"so that the results will be more reliable, consistent and accurate\".

She told me that her DD's teacher told them that \"accurate\" cannot be used. Another friend also said the same thing. Just curious, is this the latest MOE teaching concept.

I used to teach my kids that \"repeating an experiment\" will make results more accurate because it allows the \"average\" to be computed, which will help to reduce experimental error. Wonder why it is no longer valid. Hope to hear your comments. Thank you.

Hi atutor2001,

I remember from dd’s time in P5/P6, that repeating the experiment/talking more measurement gives more reliable results and not accurate results.

If the action of repeating the experimental steps/taking more measurements help to reduce random error because measurements fluctuate about some value – they are sometimes larger and sometimes smaller. So, by averaging over repeated measurements, the errors will tend to cancel and random error reduces. If random error is small we say the measurements are precise.

For measurements to be accurate, we systematic error must be small. The most common source of a systematic error is an incorrectly calibrated instrument or instruments that have zero error. Here, the observed measured measurement and expected measurement will be different resulting in inaccurate measurement if the instrument is not properly calibrated before use. Here, by repeating the measurements many times will not reduce the systematic error but only random error.

But for PSLE Science, the kids just need to understand that the purpose of repeating the steps of the experiments/ taking more measurements will gives us more reliable results. [JMHO]

[atutor2001]

Dharma:

Hi atutor2001,

I remember from dd’s time in P5/P6, that repeating the experiment/talking more measurement gives more reliable results and not accurate results.

If the action of repeating the experimental steps/taking more measurements help to reduce random error because measurements fluctuate about some value – they are sometimes larger and sometimes smaller. So, by averaging over repeated measurements, the errors will tend to cancel and random error reduces. If random error is small we say the measurements are precise.

For measurements to be accurate, we systematic error must be small. The most common source of a systematic error is an incorrectly calibrated instrument or instruments that have zero error. Here, the observed measured measurement and expected measurement will be different resulting in inaccurate measurement if the instrument is not properly calibrated before use. Here, by repeating the measurements many times will not reduce the systematic error but only random error.

But for PSLE Science, the kids just need to understand that the purpose of repeating the steps of the experiments/ taking more measurements will gives us more reliable results. [JMHO]

Hi Dharma

Thank you for your clarification. I fully agree with your explanation that repeating the experiment will not guarantee that the results will be more accurate - especially if, let say, one of the equipment is faulty.

However, I remembered coming across a question in the PSLE past year Science booklet, a past PSLE question which asked : \"How will repeating an experiment make the results more accurate?\" This question indirectly implies that \"repeating the experiment will make results more accurate\" is true and it is a PSLE question.

Hence, I was wondering if there was a change in MOE's teaching concept with regards to this aspect on experimentation.

Regards

[Dharma]

atutor2001:

Dharma:

Hi atutor2001,

I remember from dd’s time in P5/P6, that repeating the experiment/talking more measurement gives more reliable results and not accurate results.

If the action of repeating the experimental steps/taking more measurements help to reduce random error because measurements fluctuate about some value – they are sometimes larger and sometimes smaller. So, by averaging over repeated measurements, the errors will tend to cancel and random error reduces. If random error is small we say the measurements are precise.

For measurements to be accurate, we systematic error must be small. The most common source of a systematic error is an incorrectly calibrated instrument or instruments that have zero error. Here, the observed measured measurement and expected measurement will be different resulting in inaccurate measurement if the instrument is not properly calibrated before use. Here, by repeating the measurements many times will not reduce the systematic error but only random error.

But for PSLE Science, the kids just need to understand that the purpose of repeating the steps of the experiments/ taking more measurements will gives us more reliable results. [JMHO]

Hi Dharma

Thank you for your clarification. I fully agree with your explanation that repeating the experiment will not guarantee that the results will be more accurate - especially if, let say, one of the equipment is faulty.

However, I remembered coming across a question in the PSLE past year Science booklet, a past PSLE question which asked : \"How will repeating an experiment make the results more accurate?\" This question indirectly implies that \"repeating the experiment will make results more accurate\" is true and it is a PSLE question.

Hence, I was wondering if there was a change in MOE's teaching concept with regards to this aspect on experimentation.

Regards

Hi atutor2001,

You may wish to refer slide 25 of this link from a Science Workshop for Parents 2010
http://www.yewteepri.moe.edu.sg/announcementsDetail.aspx?AutoPk=133&year=2010