How does repeating results obtain more accurate results?

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aneducation
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This is a 3 mark question in an exam tomorrow, and I'm not too sure what to write.
It's GCSE ISA.
It's supposed to say accurate & not reliable...

Would this gain 3 marks ?

By using repeated results, I could detect any anomalous results and find out an average of the repeated results to obtain a more accurate result because any random errors would be excluded out.

Thank you for your help
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nataliekwong
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(Original post by aneducation)
This is a 3 mark question in an exam tomorrow, and I'm not too sure what to write.
It's GCSE ISA.
It's supposed to say accurate & not reliable...

Would this gain 3 marks ?

By using repeated results, I could detect any anomalous results and find out an average of the repeated results to obtain a more accurate result because any random errors would be excluded out.

Thank you for your help
It means you can get a wider range of results, allowing you to get a mean(average) from your results - this makes it more precise.
Good luck
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laylarose
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I have the mark scheme here for that exact question ( I did my biology ISA this past week, this question came up!) and it says:
1st mark - A statement is made that a mean should be calculated,
2nd mark - by adding the results together and dividing by the numbers of values.
3rd mark - a statement is made that either anomalous results are discarded before calculating the mean or a graph is blotted and a best fit line is drawn ignoring anomalous points.

I would go for the former statement in regard to the 3rd mark... much easier.

Hope I helped!
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ThatGirlx
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(Original post by laylarose)
I have the mark scheme here for that exact question ( I did my biology ISA this past week, this question came up!) and it says:
1st mark - A statement is made that a mean should be calculated,
2nd mark - by adding the results together and dividing by the numbers of values.
3rd mark - a statement is made that either anomalous results are discarded before calculating the mean or a graph is blotted and a best fit line is drawn ignoring anomalous points.

I would go for the former statement in regard to the 3rd mark... much easier.

Hope I helped!

I just done mine too
Hopefully I've got the three marks on that question
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Marc707
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Strictly speaking, repetition of results would increase precision, it would do nothing to improve accuracy.
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doctor_2_be
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you need to write something like this;

By repeating my results it enables you to checkyour results with those ofothers to see if there areany similarities ordifferences.With more results youare able to calculate amore accurate meanand minimize the effectof random errors. This enables reproducibility
to be confirmed.

i got three marks for this.
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Lunch_Box
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Can show anomalies when you can comparing result.

Can therefore dispute a data value and calculate a more accurate mean.
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giraffe30
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Your answer is a good one, you got your three marks for
check results with others
minimise effect of random errors
confirm reproducibility

However, having more results to generate a mean does not in itself make the results more accurate. If you have a zero error making every result biased, that won't go away in the averaging process. Random errors are spread about the mean and so they go away when you do the average.
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giraffe30
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(Original post by Marc707)
Strictly speaking, repetition of results would increase precision, it would do nothing to improve accuracy.

Actually, repeating doesn't improve precision. Precision is the spread of your results about the mean. So if your results are hugely different from one another, they are not precise.

So.. repeating doesn't improve precision OR accuracy. So you might wonder what it does improve. It reduces the effect of random errors, which MIGHT make your result more accurate as long as you don't have significant systematic errors. It also helps you check that your results are reliable ie you can get the same results over and over again (repeatable) and that your results fit with what other people found (reproducible).
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