Knowledge Claims, Evidence & Evidential

Arguments

Knowledge Claim

• a declaration of conviction

• says

• I know that or

• I believe that…

Knowledge Claim

• supported by evidence whose nature depends on the training and the experiment of the claimer

• evidence can be a first hand observation, deference to authority or a plausible explanation

Knowledge Claim

• deference to authority can range from naïve acceptance of the authority to a more careful consideration of evidence

Knowledge Claim

• e.g. I believe the Leafs will win the Cup this year.

Evidence

• data that supports the claim being made

• authoritative person is making claim. Claim is dependent on their credentials

Evidence

• e.g. I have been following the Leafs for over 30 years. I know what I am talking about.

Evidential Argument

• an argument based on the evidence that is relevant to the listener.

• Sometimes the evidence is given in the form of a critical experiment that is overwhelmingly convincing.

Evidential Argument

• e.g. you all know me and believe that I know what I am talking about.

What is wrong with my knowledge claim?

E.G. A friend says, “ I think Dr. Pop is the best soft drink.” To

convince you she says,

• “Celine Dion recommends this product”.

• 3 out of 4 people tested like it

• a nutritional analysis shows that it has less caffeine and sugar than other drinks.

Which one of these arguments would convince you?

WHY?

• “Celine Dion recommends this product”.

• 3 out of 4 people tested like it

• a nutritional analysis shows that is has less caffeine and sugar than other drinks.

Evaluating Knowledge Claims

• Is the evidence plausible?

• Does it relate to my personal experience?

• Could I do the experiment myself?

• Can I model the experiment?

• Will I achieve the same result?

E.g. The atom has a positive nucleus surrounded by negative electrons

• Earlier claims said that the atom was a mass of positive and negative regions, “plum pudding model”

• Rutherford performed the gold foil experiment

• This showed that most of the atom was empty space

E.g. The atom has a positive nucleus surrounded by negative electrons

• This led to wide spread acceptance of this new model

• Experiment was repeated several times with the same results

• Was considered a critical experiment