L17 - Inductive Reasoning Flashcards
Summaries are good for identifying what type of questions will be in the exam.
Go over at the end
When studying categories, what are we fundamentally attempting to understand in regards to our brain?
How we store and use category information in our long term memory
What is deductive reasoning?
involves using given true premises to reach a conclusion that is also true.
What is Inductive reasoning?
Inductive reasoning is probabilistic - it only
states that, given the premises, the conclusion is
probable.
- 7-10% of males are red-green color-blind.
– Joe is a male.
– Therefore, the probability that Joe is red-green color-blind is 7-10%
What type of reasoning is used for when we use categories?
Explain
Induction
Based on our conceptual representations we can make generalizations and inferences about novel stimuli
e.g we believe a new dog will act like other dogs
What was the methodology used in the Rips (1975) category-based induction experiment?
What is a blank predicate?
predicates that individuals would be unlikely to have strong beliefs about:
What did using blank predicates enable Rips (1975) to understand
the processes underlying category-based
induction in general, without having to rely on any
prior knowledge regarding the predicate.
How did Rips (1975) category-based induction experiment test for category based induction?
Employed blank predicates
– these are predicates that individuals would be unlikely to have strong beliefs about:
- e.g. robins have sesamoid bones (not a commonly understood belief*
- therefore* birds have seasamoid bones
- how many people would believe this?*
What did Rips (1975) find in regards to how we use category-based induction?
the likelihood of extending a predicate from a premise to a conclusion varied within a category
e.g. graded category structure - not all equally representative of the category
What did Rips (1975) find in regards to participants willingness to extend the blank predicate to the conclusion category varied as a function of?
- The similarity between the premise and conclusion category
- The typicality of the premise category
According to the results of the Rips (1975) study, if ducks are not highly typical birds and they are given a blank premise, how likely are people willing to extend the blank premise to a more typical bird?
Low
The induction is based on the typicality of the premise and so ducks would not extend to robins. If it were reversed, it would be more likely to extend
If a blank premise was given to a duck, would people be more likely to accept that Geese or Robins can also obtain the blank premise?
Geese, as geese are more similar to ducks than Robins
The similarity of the premise and conclusion category
Rips (1975) focused on a single premise category.
What happens when we use more than one premise category?
Adding more categories should only ever increase the similarity between the premises and the conclusion, and can only ever increase the coverage of the category
more premises means more information and stronger the stronger the argument is
What is premise monotonicity
When more categories are added to the premise the argument is stronger.
e.g. Foxes, pigs and wolves have sesamoid bones
Gorillas have sesamoid bones
Will be stronger than:
Foxes and pigs have sesamoid bones
Gorillas have sesamoid bones
What happens to premise monotonicity when negative evidence is added?
The likelihood of accepting the conclusion should decrease
What is premise diversity?
the more diverse the premise categories are, the stronger the argument:
e.g.
Hippopotamuses have a high level of potassium in their blood
Bats have a high level of potassium in their blood Humans have a high level of potassium in their blood
Should be stronger than
Hippopotamuses have a high level of potassium in their blood
Rhinoceroses have a high level of potassium in their blood
Humans have a high level of potassium in their blood
Two mammals that are similar are used to state a premise
Two mammals that are dissimilar are used to state a premise
Which argument should be stronger?
Why?
Dissimilar
Because of premise diversity
the argument covers more ground when the examples are more diverse
+ what is this an example of?
They are both equally likely.
This is The Inclusion Fallacy
What is The Inclusion Fallacy?
- We are more likely to associate a premise with a super-ordinate category rather than another subordinate category, despite the fact that the other subordinate example is from the super-ordinate category. (they should be the same chance)
This is an error of reasoning because if something is true for all birds, then it must be also true for penguins.
A reasoning error similar to Tversky and Kahnemans (1982) conjunction fallacy
What did Heussen et al (2011) demonstrate regarding the liklihood of accepting an argument using negative evidence
What is the significance of this?
sometimes negative evidence can actually
increase argument strength
This is a violation of the assumption of premise monotonicity
none of the models can account for this effect
Why did the negative evidence here end up violating the assumption of premise monotonicity?
What are the 3 argument factors that influence whether we accept a premise category links to a conclusion category?
Premise Monotonicity
Premise Diversity
The Inclusion Fallacy
