Inductive Arguments Flashcards
Inductive Arguments can be used to reach conclusions about a range of important topics
- Conclusions about an individual
- Conclusions about a population
- Conclusions about causality
- Conclusions about the future
inductive arguments
- An inductive argument can only provide probabilistic support for its conclusion
- rationally convincing (a good argument) only if it is cogent: a strong argument with true premises
strong argument
significantly raise the probability that its conclusion is true, if its premises were true.
Formal inductive arguments
- arguments in which a number is assigned to the degree of probability
- This number will be between 0 and 1 where 0 represents impossibility and 1 represents necessity
Informal inductive arguments
do not assign numbers to probabilities
–For instance, “Every time I see John he is grumpy. So, John is always grumpy.”
•In this case we generally do not have a precise measure of the probability that John is always grumpy.
cognitive bias
A natural pattern of reasoning that impedes the process of reaching rational conclusions
types of cognitive bias
- Confirmation Bias
2. Availability Heuristic
- Confirmation Bias
•“Confirmation bias” is a very important cognitive bias that often skews non-deductive reasoning.
•“Confirmation bias” refers to two well-documented phenomena:
1.People tend to be biased in favour of beliefs or hypotheses that they like.
2.People tend to be biased in favour of confirming evidence rather than disconfirming evidence, even when they are personally indifferent toward the belief or claim in question.
•In short, the second phenomenon can be articulated as follows: when presented with a claim people tend to be more inclined to confirm the claim than to disconfirm the claim.
Confirmation bias can manifest in a number of ways:
•Firstly, the searchfor evidence may be biased.
–People tend to seek out evidence that supports the claim in question.
•Secondly, the interpretationof evidence may be biased.
–People tend to interpret and evaluate evidence so that it supports the claim in question.
•Thirdly, therecallof evidence may be biased.
–People tend to remember only the evidence that supports the claim in question.
- Availability Heuristic
- “Availability heuristic” refers to people’s tendency to judge the probability of an event by the “psychological availability” of instances or examples of that event.
- The psychological availability of a scenario is determined by how easily that scenario comes to mind by being imagined or remembered.
- The availability heuristic often leads to false conclusions about probability, because the psychological availability of a scenario does not determine the objective probability of the scenario.
- The availability heuristic also skews judgements about the correlation between diseases and symptoms.
- Such correlations are generally judged on the basis of the frequency with which they occur without accounting for the frequency with which they fail to occur.
- In self-diagnoses people often significantly overestimate the probability that they have a dread disease, as scenarios involving dread diseases tend to be more psychologically available.