Assessing the use of evidence

l/o how to assess the use of evidence

Evolution explained

• http://www.upworthy.com/carl-sagan-tries-to-explain-evolution-to-an-argumentative-guy-2

Evaluate the use of evidence in this clip

• http://www.youtube.com/watch?v=jVoERKjk58c

Evidence

• We learned in the first unit to talk about whether evidence was representative– What did this mean?

– What other problems might there be that weaken evidence?

– We are going to hone our skills in assessing whether evidence backs up a claim.

Strong evidence is relevant

• Not just about the same general topic• Must be about EXACTLY the same thing– Timescale– Group of people– Geographical area

Look at this evidence

• In 2005, Detroit police used undercover surveillance and informants to fight organised criminals, and reduced crime by 43%. This shows that the UK government doesn’t need to invest money in guns – arming the police is not the only way to tackle violent criminals.

– What are the weaknesses in this way this evidence supports the conclusion?

– What ways could you say that this evidence is relevant?• Write down your answer to this question.

Evidence may be relevant but not sufficient

• Evidence may be relevant but not in itself sufficient to support it.

Look at this evidence

• Cyprus gets 329 days of sun a year – so it’s a great place for a holiday!

– Explain in your own words why this is not sufficient. Give examples of what else you need to know.

When certain pieces of evidence are withheld, then this is called selective evidence

• Many smokers use cigarettes to relieve stress – and with good reason. A scientific analysis of tobacco found that it causes the brain to release hormones that makes you feel more relaxed. Stress is bad for your health, so cigarettes are good for you.– Explain what evidence is being withheld here.– Why is this a weakness?

• For evidence to be strong, it must not be selective.

Averages are not always representative of the whole group

• Explain the difference between the mean, median and mode

Be aware

• Averages give only a rough idea of the overall group

• They may be be representative of the whole group

• Kath is a driving instructor, for eleven of her pupils, the total hours needed before passing were:

48, 59, 64, 65, 66, 67, 80, 80, 104, 129, 184

What is the mean, mode, median?

• Kath is a driving instructor, for eleven of her pupils, the total hours needed before passing were:

48, 59, 64, 65, 66, 67, 80, 80, 104, 129, 184

What is the mean, mode, median?The ‘average’ could be 67, 80 or 86

• Kath is a driving instructor, for eleven of her pupils, the total hours needed before passing were:

48, 59, 64, 65, 66, 67, 80, 80, 104, 129, 184

What is the mean, mode, median?The ‘average’ could be 67, 80 or 86Evaluate the use of evidence here: Kath is an excellent instructor. The average

time taken to pass with her is 67 hours, so no need to budget for more than 80 hours.

Write down your evaluation. Start like this….

‘For some people, it will ……

• Kath is a driving instructor, for eleven of her pupils, the total hours needed before passing were:

48, 59, 64, 65, 66, 67, 80, 80, 104, 129, 184

What is the mean, mode, median?The ‘average’ could be 67, 80 or 86Evaluate the use of evidence here: Kath is an excellent instructor. The average time taken

to pass with her is 67 hours, so no need to budget for more than 80 hours.

Write down your evaluation. Start like this….

‘For some people, it will take a lot longer that 67 hours. For others it could take less time. It might be necessary to budget for more than 80 hours, but it might take less for some.

Evaluating evidence from a graph or table

• Check to see – is it relevant? Does it give enough information?

• Pay attention to labels and keys.

Alternative interpretations of evidence

• Newly qualified drivers 17-20 are twice as likely to have a crash as more experienced drivers. This shows that the practical driving test is too easy.

– Give an alternative interpretation of this evidence.– This weakens the author’s claim

Assessing the use of evidence

• Multiple choice questions might ask you to decide which evidence would most strengthen or weaken an argument

• The average office worker spends 29 minutes of their working day making hot drinks. This is a waste of time and tea and coffee runs cost employers thousands of pounds in lost work time. Tea should be banned in all work places to improve productivity.

• Which of the following pieces of evidence would most WEAKEN the evidence?

• 1. a five minutes break every hour boosts productivity, so it is more productive to take occasional breaks than work without breaks.

• 2. tea breaks boost happiness in the workplace.• 3. office workers are more likely to day dream if given a

hot drink to drink.• 4. a cup of tea has 50mg of caffeine, and coffee 100mg.

Other questions might ask you to explain one strength or weakness in the use of evidence

The average office worker spends 29 minutes of their working day making hot drinks. This is a waste of time and tea and coffee runs cost employers thousands of pounds in

lost work time. Tea should be banned in all work places to improve productivity.

• In this argument, it is claimed that the average office worker spends 29 minutes a day making hot drinks. Explain one strength and one weakness in the way this evidence is used to support this argument.

• Be specific – the evidence is weak because……

The average office worker spends 29 minutes of their working day making hot drinks. This is a waste of time and tea and coffee runs cost employers thousands of pounds in

lost work time. Tea should be banned in all work places to improve productivity.

• In this argument, it is claimed that tea should be banned in all workplaces. Explain one strength and one weakness in the way this evidence is used to support this conclusion.

• Be specific ….

• The evidence is weak because the survey only applies to office workers.

• This is just a statement of the waekness and is not developed enough.

• The evidence is weak because the survey only applies to office workers and cannot be applied more generally to all work environments such as hospitals or schools, so it doesn’t support the claim that tea should be banned in all workplaces.

• The evidence is strong because 29 minutes is a large proportion of a day to spend on tea breaks.

– How could you expand on this?

• The evidence is strong because 29 minutes is a large proportion of a day to spend on non-work tasks; this gives strong support to the claim that productivity would improve if people weren’t allowed to make hot drinks because more time could be spent on work tasks.