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Evaluation Questions

Evaluation Questions

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9 general arguments against a drug/ treatment:
  1. Causes side effects/ side effects are unknown.
  2. Results are from laboratory tests on isolated cells / there haven’t been any clinical trials.
  3. Dosage is unknown/ not representative.
  4. The time scale of the study is too short/ unknown.
  5. A small sample size was used.
  6. Factors such as sex/age/diet weren’t controlled for/ were unknown.
  7. The cost of the drug may be too high.
  8. Cells grown in vitro may respond differently in the body.
  9. A reduced growth rate is not evidence of a cureNote: Obviously, not all of these can be applied to every question, and this isn’t an exhaustive list.
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2019 As Paper 1 Q9.4 (3 marks)

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2025 As Paper 2 Q3.4 (5 marks)

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June 2012 As Unit 1 Q7(e) (2 marks)

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2020 A-Level Paper 3 Q05.3 (3 marks)

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In general, why are control experiments important? (2 points)
  1. They allow comparison with other experiments/ treatments.
  2. They show the effects of whatever is being tested.Note: In an exam question, make it specific to the experiment by saying something like ‘it shows the effects were caused by substance X, not the agar gel the plants were placed in’.
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2015 A-Level Unit 5 Q9(e)(i) (2 marks)

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2 benefits of taking random samples:
  1. Avoids bias.
  2. Makes the results (mean) more reliable and repeatable.
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2021 As Paper 2 Q6.2 (1 marks)

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January 2012 As Unit 2 Q7(a)(ii) (1 marks)

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In a question about whether correlation proves one variable affects another, what should you always say? (2 things)
  1. Correlation doesn’t equal causation.
  2. Another factor may have been involved.
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2019 A-Level Paper 1 Q2.2 (4 marks)

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January 2011 As Unit 1 Q4(b) (3 marks)

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June 2011 As Unit 1 Q2(c) (3 marks)

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What are the 2 ways to make samples more representative?
  1. Make them random, either by picking randomly using a hat or using a random number generator.
  2. Use a large sample size, or keep sampling until the running mean remains stable.
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2019 A-Level Paper 1 Q3.2 (2 marks)

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7 general things you can say to critique a graph/ experiment:
  1. Only one study was done/ only X people were involved, making the sample size too small for reliable and representative results.
  2. There is a weak correlation.
  3. No statistical tests were done.
  4. The standard deviation bars overlap, showing the difference wasn’t significant.
  5. The time period is too small.
  6. No control group was used.
  7. Details on age/ sex/ diet weren’t given.
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2017 As Paper 2 Q7.2 (3 marks)

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2025 As Paper 2 Q3.4 (5 marks)

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2015 As Unit 2 Q9(c) (5 marks)

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2016 A-Level Unit 5 Q9(d)(ii) (4 marks)

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2 reasons why it is important patients record their pain using a ‘statistically valid scale’ in an experiment on pain:
  1. Pain is subjective and pain tolerance varies.Note: I’m not sure how the scale changes this.
  2. It ensures the differences in pain were statistically different, allowing valid comparison.
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2023 A-Level Paper 2 Q2.4 (2 marks)

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Why should a drug be dosed per unit of body mass in a study?

To allow valid comparison as participants vary in mass.Note: you could have also said ‘so concentration of the drug in the blood is the same in all participants’.

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2022 A-Level Paper 2 Q8.2 (1 marks)

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When a study is done on rats, which two points should you always make?
  1. As an argument in favour of the study, say that ‘rats and humans are both mammals, so they are similar.’
  2. As an argument against the study, say 'the study was done on rats, so we don’t know if the same effects would occur in humans.'Note: always make both points - they can appear on the same mark schemes together as valid for and against arguments.
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2025 A-Level Paper 3 Q2.3 (5 marks)

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3 ways a double-blind trial improves reliability:
  1. Prevents any bias.
  2. Prevents the scientists being affected by vested interests.
  3. Prevents the placebo effect playing a role in the volunteers.
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June 2010 As Unit 2 Q8(d)(i) (2 marks)

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2014 As Unit 2 Q9(a)(i) (2 marks)

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What are 2 reasons you would not be able to extrapolate a graph?
  1. The graph not being linear.
  2. The graph having large fluctuations.
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2024 A-Level Paper 3 Q6.4 (1 marks)

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Why is it important that scientists report the findings from failed experiments? (2 points)
  1. It saves time and money for others.
  2. This is because it means the same work isn’t repeated and the methods can be improved upon.
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2012 A-Level Unit 5 Q5(c)(ii) (2 marks)

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2 scenarios where you should use the median over the mean:
  1. There are outliers.
  2. The sample size is small.
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2019 As Paper 2 Q05.5 (2 marks)

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