‘Step-by-step’

Assessing Arguments:

AuthorshipWho says so?

AuthorityWho is he/she?

ProvenanceIs this a primary or a

secondary source?

Context

Evaluating

evidence’s

credibility &

relevance

When was it reported?

Is it focussed?

Is it representative?

Nature

Facts or opinions?

Accuracy

Is it accurate?

Are his/her views

shared?

STRUCTURE

CLARITY

EVIDENCE

LOGIC

EVALUATION

1

2

3

4

5

How to assess arguments?

5 Steps:

STRUCTUREStep 1

• Evidence

• Conclusion

Identify:

Two thousand years ago, the Earth was home to just 300 million humans, roughly the

population of the United States today. Two hundred years ago, 1 billion humans lived

on our planet Earth. The world population is now at over 6 billion and growing rapidly.

Thus, if current trends continue, we will add another 1 billion to the world population

every 13 or 14 years. (Extract from www.umac.org/ocp/CausesofGrowth/info.html)

CLARITYStep 2

Identify: • Any vagueness?

• Any confusion?

• Any assumption?

EVIDENCEStep 3

Assess: • Credibility

• Relevance

LOGICStep 4

Identify fallacies

FallacyMisleading or unsound argument

Mistakes in logic that are

independent of the

argument’s content.

(Flaws in the form of the

argument)

Formal fallacies Informal fallacies

Mistakes in logic that

arise from the content.

(Flaws in the content of the

argument)

Informal fallacies

(Only uses evidence that seem to confirm a particular position, while ignoring a significant portion of evidence

contradicting that position)

• Cherry picking

(assumes that correlation between two variables implies that one causes the other)

• Correlation proves causation

“Whenever I clean my car, it rains.”

(offers only 2 options when many more are possible)

“To lose weight, you either stop eating fries or have liposuction”

• False dilemma

• Ad Hominem

Informal fallacies

(attacks the opponent rather than the argument)

(uses emotion rather than evidence)

( questions the motives of the proposer to dismiss the proposer’s point )

(misrepresents the opponent’s argument)

“Prof Popper believes that an increase in rainfall will destroy crops but if there was no rainfall crops

would not grow in the first place”

“We must stop climate change or your children will drown under rising sea levels”

• Straw man

• Appeal to emotions

• Appeal to motive

“Of course Prof Popper says climate change is dangerous! She holds the Chair of

Innovation in Heuristic Climate Change Modelling”.

“What does Prof Popper know about global warming? She drives a Range Rover”.

STRUCTURE

CLARITY

EVIDENCE

LOGIC

1

2

3

4

5 Steps:

How to assess arguments?

EVALUATIONStep 5

Is the argument clear, with

valid evidence and logic ?

Strong

argument

Weak argument

Yes

No

STRUCTURE

CLARITY

EVIDENCE

LOGIC

EVALUATION

1

2

3

4

5

How to assess arguments?

5 Steps:

Global Challenges

Infectious diseasesPopulation

Climate changeObesity